19 years old & English - this was kind of obvious, really.

In my experience, people interested in hacking and infosec over the age of 25 are more likely to know about 2600 and hold it in some regard, unlike those younger than 25. Hence, it was pretty clear that lulzsec was comprised of under 25 year olds.

They also engaged in some very unlulz-y personal wars with a few people, and didn't quite seem to know limits - very much a young person trying to prove themselves too hard sort of thing.

Similarly, they hacked a number of British sites, and something about their use of langauge sounded to me, as an former forum moderator, to be rather British. 2600 is also less well known over here.