Well it does make sense when you consider the number of disaffected youths turning to online gaming as a source of escapism. Extremists thrive in an environment where the targets of recruitment are disconnected from their society, after all, it's how Hitler came to power after WW1.
The theory makes sense given the number of youths into online gaming not only in the Middle East but also in places like South East Asia, where Jamar Islamia thrive. So, the theory holds up. But of course, communism works on a theoretical level.
And of course, the likelihood of finding a level 60 paladin who secretly wants to bomb the US embassy are quite slim at best.