Do you think another 51% attack will happen?

[5thStreetResearch]

when was the first one?

[MakeBelieve]

when was the first one?

There was never a first one I think the OP made a mistake 51% attack I don't Bitcoin would be as popular as it is now.

[Krox]

So you would need 5,372 of those bad boys to get 51%.  That's a $54 million investment in hardware.
...
So there's really no economic incentive for performing a 51% attack for the purpose of double-spending against Bitcoin.

That doesn't mean it won't or can't happen, it just means the likelihood of it occurring is pretty small.

For a government wishing to destroy bitcoin because it competes with their fiat currency, investment of $54 million USD will be considered cheap. Likelyhood of such attack may not be so small. Gov can wreak havoc by doublespending, or by not allowing arbitrary transactions. Probably was at least considered at some government level. The effect of having 51% is not completely devastating, as it is not possible to just steal wallets, but can land a big blow to trust in bitcoin.

[Mobo]

I hope not       

[Sonny]

when was the first one?

There was never a first one I think the OP made a mistake 51% attack I don't Bitcoin would be as popular as it is now.

Yup, I guess OP misunderstood the word "51% attack".

[Sonny]

Gnash.io came close by almost having 51% of bitcoins mining power in their pool but they've said they're putting measures in place to make sure it never reaches 51%. If it was a more unscrupulous group then maybe things could have gone badly but who knows if it will happen in future. Remember that if someone does do it, their own bitcoins would likely become worthless too.

Almost coming close to controlling 51% of the hashing power for a short time is not an "attack".

Indeed, we had this kind of worries (or FUD) back in 2011, when Deepbit was getting bigger and bigger.

For the love of god, point your miner away from deepbit: https://bitcointalk.org/index.php?topic=13345.0
Deepbit at about 49%: https://bitcointalk.org/index.php?topic=26656.0

[torezo]

I will happen someday when btc is big enough, there will alwas be sabotagers.