Trains cancelled over fake bridge collapse image

To be clear, you don't need AI for this.

You can also just call the railroad and report the bridge as damaged.

Hoaxes and pranks and fake threats have been around forever.

That leaves much more of a paper trail. People routinely are fined and jailed for pulling off such "pranks", partially because "fake threats"/"abuse of emergency response resources" are an exception to many freedom-of-speech laws.

A fake photo of a collapsed bridge however won't cross that criminal threshold.

If you create a fake photo/video with intent to cause disruption it absolutely crosses the threshold.

If you create one to prank your friend, and he ends up falling for it and sharing it in another group, and it gets to someone who alerts the authorities, without including the context of "this was sent to me by a guy who's a bit of a joker", and railway management's policy is to take all reports seriously rather than verifying their provenance...I find it hard to think anyone in that chain should really be held liable.