I guess the past few responses to me have made it clear that people on this thread don't want to discuss or solve things, but merely make strawmen and misrepresent the reasonable statements of others.

That sounds even more centralised than mining already is.

It's abuse because you're forcing others to download/store your data against their free choice.
Every full node must download the full blockchain (prunable or not!).
Every full node has consented to download and store financial transactions.
NOT every full node has consented to store anything else.
You need 100% consensus for this, not merely some subset (ie, not miners; not developers) or even a majority.

Furthermore, everyone is free to store data that isn't in the blockchain.
There is nothing to be gained by putting it in the blockchain except that you force it on those who don't want it.
Explain how this is anything but abuse...

Miners are not supposed to decide protocol changes any more than developers.
Protocol changes, in general, require consensus of the economic majority (or, more practically, "will this person I want to pay accept my forked-blockchain bitcoins?").

Not exactly. Miners certainly have the ability to decide which transactions they do and don't include, but they have a duty to use that ability to protect the system from abuses.

The miners have that duty.

These are the same question.

Bare multisig transactions are not currently used. It's quite possible to turn them off without breaking anything that actually needs multisig-type use.
Furthermore, it's quite possible to determine what multisig usage is actual multisig and which are data store abuses.
So yes, there is a choice...

"Reduce"? No. OP_RETURN was increased from 0 to 40 bytes.
And no, "don't abuse us with OP_RETURN" does not mean we are forcing you to abuse us in other ways.
If we lock the windows, we aren't forcing the burglar to break them. Stop trying to blame the victim.

I haven't looked at XCP in detail yet, so I'll have to defer to others who have.

Merged mining, and/or hopefully soon bitcoin side-chains.

Because:

• Too many people were getting the impression that OP_RETURN was a feature, meant to be used. It was never intended as such, only a way to "leave the windows unlocked so we don't need to replace the glass when someone breaks in". That is, to reduce the damage caused by people abusing Bitcoin.
• 40 bytes is more than sufficient for all legitimate needs for tying data to a transaction: you get 32 bytes for a hash, plus 8 bytes for some kind of unique identifier (which really isn't necessary either!).
• The original 80 byte proposal was intended to be for 512-bit hashes, but this was determined to be unnecessary.

Zero bytes is exactly how it's intended to be.
Note the OP_RETURN change by the development team is only a change in default relay policy.
Miners are, as always, expected to make their own policy decisions, and never rely on merely the default Bitcoin Core mining code.
Hopefully as mining returns to being decentralised, we will see less toleration of abusive/spam transactions whether the OP_RETURN variant or otherwise.
Now, if someone has a valid, necessary use case for actually storing hashes with transactions, obviously that's a case miners should seriously consider mining.

The miners are supposed to filter out abuses.
Human problems need human solutions.

The problem isn't new layers, it's forcing things on people against their will.
New layers can be done on an opt-in basis, without polluting the blockchain and forcing non-participants to store the data.

The Receive page has been revamped to make it easier to use correctly.
If you're trying to use addresses wrong, it will be slightly less convenient as you go to the menu...

Bitcoin as a whole has always been beta/experimental.

Just wondering, but does anyone know if this is recognised by Israel?
At least in the US, companies are not allowed to void warranties for reasons like this (ie, unless you actually caused the damage).

There is really no good way to do this with Bitcoin.

FYI: BTC is always a period as a fractional separator, even in locales where comma is used for fiat.
This is important for Bitcoin to function properly as an international currency.

Your threat to abuse multisig is no different than a thief telling his victim "leave your windows open for me or I'll break them".
Even in the rare cases where some data storage is needed, 40 bytes is more than enough for reasonable uses.
The only arguments for more, always come down to "we want to force people to store our data against their will".
Stop abusing Bitcoin. Thanks.

... or any browser plugin, or any other software on your PC, or github gets compromised, or ...

Did you know that Javascript lets you redefine the Number class such that every constant is always 42?
Things are not always what they seem, even if you use their code-audit plugin...

Armory supports true paper wallets.

+1 to always keeping an up-to-date backup of your wallet!

Mostly speculating. They like to portray themselves as more secure, when they're really not.

blockchain.info is probably going to be the next MtGox...

Correction: By default, IPs are only logged when a node connects. This is still a potential concern, but was introduced in 0.7.0, not 0.9.0.

Not merged yet.

It is always on and cannot be disabled in this release.