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2281  Bitcoin / Technical Support / Re: Bitcoin taking up 5.6gb on my computer on: December 25, 2012, 09:19:35 PM
I thought the blockchain was supposed to be <4gb. Whats up with that !?

That was several months ago.  It grows quickly because there are thirty to fifty thousand transactions each day and the blocks are stored in raw form (not optimized).

This space issue will be reduced to some degree with Bitcoin v0.8 but more importantly the performance will be much faster such that you feel you need to have the Bitcoin data on your SSD drive.
 - datadir= 
should help you in the meantime.
2282  Other / Beginners & Help / Re: help! prepaid visa to bitcoin? on: December 25, 2012, 02:46:25 PM
i've been trying to figure this out for a while now, it seems there really is no easy way to do this...
any way i can mail in my card and recieve btc? i have little worries about doing this fast, i just want it to work and be easy enough for me to figure out.

There had been an exchange or two that had offered this method in the past, but currently there are none.   

Bitcoins can be bought with cash.  A prepaid VISA card can be used at an ATM to obtain cash.

If you still want to try to find a trade, you might post an offer on the #bitcoin-otc marketplace.  Maybe someone there will be interested, at the right price.  Just make sure that if you are going to send the card in the mail that the party you are sending it to has a decent trust history in the #bitcoin-otc Web of Trust (WoT).

2283  Economy / Marketplace / Re: Sell That Gift Card For Bitcoins, PayPal USD or an Amazon Gift Card on: December 25, 2012, 02:35:38 PM
Additional gift card exchanges include

From a 2012 review on USA Today:

I see there is one that I had missed:

2284  Bitcoin / Development & Technical Discussion / Re: possible to avoid double spends if accepting unconfirmed transaction? on: December 25, 2012, 02:08:10 PM
thus reducing the risks of a double spend. where basic terms/conditions of satoshi dice/coffee shop are that only transactions from an address with low activity will get accepted for instant use. where by addresses with alot of activity would have to wait for confirmations before the trade/sale/service is completed.

Just to clarify, there's no period of time (e.g., an "hour") that will ensure that a transaction has confirmed.  So this idea of requiring that an hour doesn't guarantee anything.

Also, it appears you are placing significance on this concept of an address having "low activity'.  Bitcoin does not use the concept of "balances".  Bitcoin transactions instead consist of inputs and outputs.  Once an output is spent, there is no further activity for that output, ever.

But you are right to express a concern.  Consider the following scenario:

Let's say SatoshiDICE made payouts using other people's wagers that hadn't yet confirmed.  And then a consumer uses the funds from that SatoshiDICE payout to make a payment at a merchant.  Then let's say those transactions never confirm and somehow further back a double spend occurred and invalidated the wager to SatoshiDICE.    What ended up happening then is that the consumer made a payment to a merchant that will never confirm.

But that is easy to identify.  The merchant needs to do more than just check that the transaction was received but also check that the input(s) for that transaction had at least one confirmation (or perhaps more confirmations, depending on the amount of the transaction / level of risk tolerance).

Accept 0-confirmation tx = trust the payer. If you do not trust the payer, you should wait for confirmations.

In the example above, the customer might have been trustworthy but probably would have been at the time unaware that the funds being used to pay the merchant hadn't been already confirmed.    So in that instance, even though the consumer had no intention to double spend that is indeed what could occur if the consumer too ended up receiving a transaction that eventually became a double spend.

So the litmus test on accepting 0/unconfirmed as payment might need to also include another check to ensure that all inputs for the payment had confirmations.  If that fails, then there is an increase in the risk of that transaction never confirming and the merchant would want to proceed in an appropriate manner.

These type of scenarios will rarely occur accidentally, so simply the prevention could be to ensure that there is no economic gain from attempting them.  A restaurant for instance will make more in profit from repeated failed double spend attempts than it would lose from the occasional one that does occur, for instance.   

But a merchant will probably want to use a payment processor that can perform the risk analysis (e.g., to know that if the payment to the merchant came from a SatoshiDICE payout that also hadn't confirmed that it then is a higher-risk payment.)
2285  Economy / Scam Accusations / Re: Scammed by Bitexchange [265 GBP] [~30btc] on: December 25, 2012, 12:58:58 PM
My takedown request to the hosting company for was denied because I personally wasn't reporting having been scammed.

So to get a takedown, others who were scammed will need to report this, as the hosting provider's response stated:

if you could provide us you where scammend we will shutdown this site

Send an e-mail to:
2286  Other / Beginners & Help / Re: Sell bitcoins for wire transfer (SEPA and ACH),WU, PayPal, Cash on: December 25, 2012, 12:57:04 PM
I've submitted a complaint to, hopefully they will take action.

My takedown request was denied because I personally wasn't reporting having been scammed.

So to get a takedown, others who were scammed will need to report this, as the hosting provider's response stated:

if you could provide us you where scammend we will shutdown this site

Send an e-mail to:
2287  Economy / Service Announcements / Re: [ANN] Safe JavaScript Bitcoin address/private key on: December 25, 2012, 11:14:33 AM

I can verify that the website has been updated and returns the same HTML from the commit with the description v2.1 (d34b4f7f9a219293238f93507617586f5ba4db17) in github:

To confirm this I first check the sha1sum hash of the html returned by a request to

$ wget --quiet -O -|sha1sum
af431934553aeef3e042e796a31ee101cdabc496  -

$ GET -eSd|grep -i "200 OK"
GET --> 200 OK

Then from my repo:

$ git checkout master
$ git pull
$ git log --pretty=oneline|grep "v2.1"
d34b4f7f9a219293238f93507617586f5ba4db17 v2.1 Vanity Wallet add/multiply public/private keys. Code refactors.

$ git checkout d34b4f7f9a219293238f93507617586f5ba4db17
$ git rev-list --max-count=1 HEAD

$ sha1sum
2288  Other / Beginners & Help / Re: i think i did something wrong on: December 25, 2012, 01:25:50 AM
today a was funding my virwox account and testing it sending 0.5btc but then i got the error: transaction creation failed , any help with that?

With the client if your wallet contains a lot of microtransactions, such as those coming from the free bitcoin sites, or the losing transaction payouts from SatoshiDICE, or from a mining pool with the payout threshold too low, then you've hit a scenario that the client doesn't deal with very well.

One workaround is to break up your spend into several transactions using smaller amounts.  Choose a smaller amount and send that amount to an address not in your own wallet (e.g., to an Instawallet or some other EWallet).  Then do another one and continue until all the funds from these small transactions are spent.  

Another workaround is to import the private keys into another client that doesn't have this same problem.

It is possible this issue will no longer occur with the next release of the client (v0.Cool since much of the database code has been reworked but there's no ETA yet on that.
2289  Other / Beginners & Help / Re: NVIDIA Tesla C2075 Server Rack Cluster on: December 24, 2012, 10:19:07 PM
Even with the Tesla power? These are pure GPU servers.


Now you might want to take a look at what CoinLab is creating.    They are building a client that you run and earn bitcoins.  It will performing computing tasks, not necessarily be used for bitcoin mining.  They are still working on the HPC client (which will do much better on NVidia than AMD).  Currently, they just operate a mining pool though.
2290  Bitcoin / Mining support / Re: Advise needed on: December 24, 2012, 09:56:49 PM
What are the best ATI cards to mine with and ones that are cheap to buy and provide good hasrates.

I hate to be debbie downer here, but GPU mining is just about done for.  If you pay anywhere near ten cents per kWh or more, you are losing money with each hash.

i.e, There are no pros and cons, because there's just no sense to buying GPUs for mining at this late stage of the game.
2291  Other / Beginners & Help / Re: Melting Coins? on: December 24, 2012, 09:55:03 PM
Does anyone have experience with actual melting of coins? If someone was to horde physical coins with the expectation of trading them in for their base value in the future, how would one go about it? Who would buy the base metal?

There's a bitcoiner learning the ropes right now.  Here's a video of him creating an ingot from melted jewelry and other scrap:

There's a little backstory there to be sure.

But that shows the amount of effort to convert silver items to silver usable for trading and why physical silver is sold above spot market rate.
2292  Other / Beginners & Help / Re: scam or legit? on: December 24, 2012, 09:21:00 PM
They took me for nearly $13K.

Bitcoin is starting to pressure these digital currency exchanges.  

Where they used to get 6%, or 8% to convert funds, they instead are now facing competitors like AurumXChange, which takes a minimal fee (1% for LR --> Mt. Gox,  2.5% for Mt. Gox --> LR).    So some of them turn to running scams (or increase the level of scamming they perform).

If they only scam the larger transactions, they can keep their long confidence game going (by processing successfully the smaller transactions, which gives the customers confidence to continue using the service except with larger transactions.  That works until one day, bam! Scammed.)
2293  Bitcoin / Development & Technical Discussion / Re: possible to avoid double spends if accepting unconfirmed transaction? on: December 24, 2012, 08:50:13 PM
i ask this as some businesses are trying to figure out a way around the 10 minute confirm times by atleast seeing the transaction history of the customer

i see on blockchain info that it does list transactions even without a confirmation. is there a way for EG satoshi dice to check the senders address for any other transactions that they have sent within the last 5 minutes before the satoshi dice received theirs and decline the payment for instant use if there was more then 1 unconfirmed transaction within 5 minutes prior to the transaction.

meaning that customers who only do transactions with atleast a 5 minute gap from a previous transaction elsewhere will get an acceptable instant use acceptance.

Are you referring to how a merchant might receive a transaction that itself is based on a prior transaction that has not yet confirmed? 

If so, then yes that can be determined either from the blockchain or with the help of third party services such as

The client doesn't let a transaction use a coin that has not confirmed (unless it is change from a previous transaction) but other clients don't have that restriction.

2294  Economy / Service Announcements / Re: PicoStocks, bitcoin stock exchange on: December 24, 2012, 08:07:12 PM
The main concept of the new model is that PicoStocks is the legal owner of all assets.
PicoStocks is a legal person established under the jurisdiction of Marshall Islands.

I've been wondering how long before someone takes this approach.  More overview of Marshall Islands:

The FAQ gives additional useful info:
2295  Other / Beginners & Help / Re: Large Scam on: December 24, 2012, 07:31:03 PM
Check Talkgold forums for numerous complaints against them.

Another thread on the topic: scam or legit?
2296  Other / Beginners & Help / Re: The Best Bitcoin Exchanger? on: December 24, 2012, 07:23:33 PM
Dear Members,

Please share your experience, which website, exchanger, service is the best in case I need to exchange bitcoins to any
other e currency like Liberty Reserve, Perfect Money, Bank Wire or are there any debit card service?

To Liberty Reserve your options are:
  AurumXChange, BTC-e,, Vircurex, and a number of e-currency exchanges like ECurrencyZone, Lillion Transfer, WM-Center, etc.

 -  <--- Now takes Bitcoin directly

To Perfect Money your options are:
 AurumXChange, BTC-e, ECurrencyZone, and WM-Center.

For bank wire (presuming you are asking about domestic transfer) and debit card transfer will depend on where you are located.

A fairly comprehensive list of exchanges:

2297  Bitcoin / Bitcoin Discussion / Re: Is it just me or do ALOT of bitcoin sites look just awful? on: December 24, 2012, 07:07:24 PM
What do you guys think?

Bitcoin sites serve a small subset of the population and aren't necessarily big earners.

Good design is expensive with costs are incurred up-front.   A few Bitcoin-related services are generating profit right off the block (e.g., SatoshiDICE) so as to be self-supporting but most others would require the investment to be able to pay for UX and design help.  Bitcoin businesses don't have the same type of investor base as most other e-commerce and online businesses, so even if a programmer who launched a service wanted to get a better design and is willing to give up equity to do so, there might not be any investors willing to make that leap of faith as well.

When there's money to be made, better design will be a component that differentiates services.    In the meantime, a service that competes by being lean and functional trumps being beautiful.
2298  Other / Beginners & Help / Re: Request on: December 24, 2012, 11:26:16 AM
Just for future reference, you can also trade to and from MoneyBookers using VirWoX:

But there were better offers here from others.
2299  Other / Beginners & Help / Re: want to buy GBP on: December 24, 2012, 11:24:29 AM
hi everyone last time i was asking if someone knew how i can exchange bitcoins into GBP in my moneybookers account, so i failed to find a way.
Thats why i am here looking for a seller (want to buy 15.00 transfered to my moneybookers account)
any help in would be apreciated.see ya

You turned down bcb's offer.  Then you post here that you still need to do a trade? Am I missing something?
2300  Other / Beginners & Help / Re: Pre-Paid Debit Card to Bitcoin (VISA, MasterCard, gift cards, etc.) on: December 24, 2012, 11:01:47 AM
The subject pretty much says it all.  I always see trading sites that offer prepaid cards for bitcoins, but I never see any that accept them and give you the bitcoins. 

There had been a few individuals or exchanges in the past that would take this.  The fees were in the 10% range.

A prepaid debit card usually will function at an ATM.  There are many methods for buying bitcoins for cash.  That might be your best option.

For instance, with Bitme you can deposit cash at any Chase bank location and the funds will be credited to your exchange account:

There is also where you deposit cash at 7-11, Walmart, CVS or any Moneygram location:

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