And how would you prove intent? It might be easy to prove if it's an usb drive with only a zip bomb. But what if it's on a 8TB external hard drive, with a bunch of random stuff (research papers, movies, podcasts, etc), placed inside a folder called "DoS examples" with a bunch of other malformed files as well?

Isn't the American legal system the one where that kind of argument actually has weight? Why so many cases are thrown out on technicalities and litigation costs are so high.

Because we're talking here about a file that one might possess within one's personal effects and papers--a file, on a PC, with no desire whatsoever to share it with anyone--the comparison to waving a knife around while screaming threats, or forcing a malicious file into a server, seems more than a little thin. Where is the motive? Where is the criminal frame of mind?

Remember, piping /dev/zero to a compression routine for a few seconds, out of curiosity or testing a shell script or whatever, could create a file that might throw a wrench into poorly-built works.