MPAC UK implies some UK Muslims guilty of treason
http://www.mpacuk.org/content/view/4870/102/#jreactions
So, when Muslims in polls state they support suicide bombings (hence attacks possibly against UK citizens as in 7/7), and Muslim who state that 7/7 was justified, any Muslim who goes abroad to fight against British troops etc are also guilty of treason by this logic.
We think that anyone prepared to fight against the people of your home country are potentially guilty of treason. However, we don't see people with sympathies for Israel bombing the hell out of their fellow citizens, or planning to.
The Useful Idiot