At this point rechargeable lithium-based batteries are a more effective bomb than 90% of the things the TSA has banned - but I suspect we won't see them trying to take away laptops and phones anytime soon.
The TSA are a funny bunch. They've searched through my 80 year-old grandma's bags and confiscated her paint. Yet, when I mentioned that the metal detector failed to detect my solid metal watch, the agent said "it's ok - keep going".
Critical thinking is not part of the curriculum. There's a rule stating that your grandmother's paint must be confiscated, but no rule stating what happens if the metal detector is suspected defective.
On a recent flight he check-in person asked me if there was any lithium battery powered devices in the stow-away luggage. I think they are looking for things with big batteries like power drills and things like that, which presumably can pack a punch if they go wrong.
At this point rechargeable lithium-based batteries are a more effective bomb than 90% of the things the TSA has banned - but I suspect we won't see them trying to take away laptops and phones anytime soon.