[simias]

To what end would the GCHQ DDoS IRC servers? What would they gain from that?

[meebi]

According to the leaked documents, denial of the targeted users to communicate with each other.

[Cthulhu_]

Basically, jamming communications between internet terrorists / freedom fighters (depending on your stance on the matter)

[ersii]

And/or just regular people who chat with each other.

[valarauca1]

EMP'ing the telephone exchange hopping to cut off the bad guys phone calls to each other.

[a3n]

Telling their boss that they did something.

[zecho]

DDoS has also been used to cause netsplits, which can then be exploited to gain access to private rooms.

[meebi]

On any sensible IRCd this won't happen. Users sneaking in during netsplits will be booted as netriders when the split closes.

[phusion]

They wanted to stop AnonOps from enabling the planning and execution of Anonymous operations. They bragged that a month after "rolling thunder" that the same nicknames/operations weren't there anymore. It's hardly effective, mostly childish.

[TuringTest]

That news is covered here:

http://blogs.csoonline.com/other/2979/irc-network-calls-inve...