"isn't there already enough actually substantively problematic about new social movements that it's unnecessary to resort to the right-wing tactic of comparing everything we don't like to terrorists?"
I don't think that Phil Cunliffe was comparing nsms to Islamists to describe nsms, but to describe Islamists.
If I read him right he would agree with you that there is something substantially problematic about nsms, namely their anti-mass character, and that these are characteristics they share with modern-day Islamism.
(And isn't this just Trotsky's argument about the inner link between terrorism and reformism?) -- James Heartfield The 'Death of the Subject' Explained is available at GBP11.00, plus GBP1.00 p&p from Publications, audacity.org, 8 College Close, Hackney, London, E9 6ER. Make cheques payable to 'Audacity Ltd'