I mean that we only use what were given so the caller can decide what we see so maybe thread safe isn't quite the right expression.  I think that we never get a different model but we can end up with a different database session on occasions so we should use `context['session']` not `context['model'].Session.  I only know a small amount of where the session issues arise but they do ie we need the other session..  This is something that maybe could be changed/documented better.

Keep these questions coming.  The only thing is that they can end up a bit contained in github and at a point need to break out into the dev-list so everyone gets to have their input.  Maybe this is one?