Comment 144 for bug 604635

(In reply to Justin Lebar [:jlebar] from comment #111)
> Hm...actually, mListeners can be modified while we iterate over it (we're
> running arbitrary script). I wonder if we handle this elsewhere (e.g. by
> making a copy).

Someone told me that DOM is single threaded so I didn't bother to check that. But yes, the service might be accessed from other threads :-/