I've got mixed emotions about this one. Yes, we used to blow stuff up as a kid and do a lot of things that would be considered unacceptable today (in some communities anyway). But we didn't destroy peoples property or do something that might get somebody seriously hurt (other than ourselves). Putting an explosive device on someone's porch is not a joke.
If I was the homeowner and some damn kids set an explosive device on my porch and damage was actually made...yeah, I'd want to teach them a lesson with the law. That's for sure, but I wouldn't expect them to get a felony and prison time. Hell, at that stage of a kids life, they're going to say "screw it, I'm already a felon." What lesson is there left to learn? It should be a misdemeanor with additional stipulations such as community service or other program to educate them on how stupid and dangerous it was to have done something like that.