I've said it once, and I'll say it again even at the risk of being banned.
There is no way on this planet that 100g of PETN could bring an aircraft down, it's inside a printer cartridge, in a printer, in a container.
As decent an explosive PETN is, I really don't think it would have caused that much damage. (Cue somebody going on about Lockerbie etc).
We've already had the ridiculous liquid rules enforced on us, are we now going to have powder rules?