DOSing the major pools isn't what I think of as a "51% attack", but whatever. Whether or not the pools are under attack or not is of little concern to myself. The overall security of the network is not really under threat, since 10 Terahashes per second isn't a mark reachable by any known network or supercomputer. This does highlight the risks to the bitcoin network at large associated with pool mining. Concentrating the mining to a single server for the purpose of income stability also creates central points of failure/attack. I don't mine in pools for this exact reason, and don't think anyone with any substantial hashing ability should do so. 10K small lights are harder to shoot out than a dozen really big ones.
No but if you had say 4TH of computing power knocking (or trying to) the largest pools off the network could be a precursor. The 3 largest pools have ~6TH combined. The 5 largest pools have ~7TH combined. Disrupting the network softens it up for a 51% attack.
Still it looks like operator of BTC Guild thinks this happened because he pissed off a botnet operator (by blocking him from his pool)
I don't think it is something you did. Slush indicates his pool is under attack and deep bit users are indcating connectivity issues.
I'm referring to the fact that this all happened a few minutes after I posted that I had submitted a giant list of IPs that I had been collecting from the botnet miners the last few days. Could very easily be the childish mentality of these "hackers": "Oh yeah, well I'm going to take my ball and go home, but first I'm going to pop your ball."