Firstly, you don't have to be a "terrorist" to blow something up, and there are plenty of fucked up individuals out there who know how to make explosives. And these days, everybody's got a bone to pick with everybody else. If you're going to go to all the trouble of putting obscene audio recordings in a church, why is it so far fetched that you might want to cause further damage? Obviously the fact that they moved the things would be an indication they weren't dangerous, but it still seems a lot more logical than the Boston thing. Secondly, I don't think that would be particularly funny. You probably wouldn't either if you knew any cops.