It's absolutely illegal and 7chan has already claimed their fame to doing something of the sort. These things bother me, I mean moot/m00t/whatever the hell else people address him by said it himself; these pointless DDoS raids or Invasions of the such are funny, and harmless. But Mr. Internetz Tough-Guy posting something like "I haTe ThiZ Faq, tEar 'Em uP!" followed by a myspace link on /b/ is retarded. Anonymous has "torn up" the idiot posters numerous times - which I approve of. Just saying; hope you aren't planning anything.