Looked like you were serious so...
The .40 glocks have a very unsupported bbl which can sometimes lead to a case rupture during firing. Usually does a number on the frame, blows the mag out and generally scares the hell out of those nearby. Haven't heard of anyone actually being hurt by one (yet.)
From what I've seen the problem is typically with slightly over-spec ammo, even factory ammo can be shipped over spec. IIRC a batch of Federal Hydrashocks was over pressure a while back, haven't heard of anything since then. If you look at a fired case you'll see a pretty large bulge near the rim, this is where the kaboom happens.
I think there was a PD in the Pacific NW not too long ago that had a .45 Glock KB on them. Not sure if was an ammo or gun issue though.