Keeping a Backpack of Empty Fireworks Out in the Open in Your Dorm Room

Yeah, that makes sense.

Not.

Also too--

The amount of gunpowder that could be harvested from the kits – less than a pound and a half – would not have been enough to detonate the Boston bombs, company Vice President William Weimer said, although it's possible some of that powder may have been used.

The absence of colored smoke in the Boston explosions and other special effects powders mixed in with the fireworks' blast powder suggests the bombers sought and used an alternate fuel source, he said.

"My suspicion is they experimented with this, decided they couldn't get enough powder out of them and went to look for another fuel," Weimer said.