[a_wild_dandan]

Across the internet spreads a noisy video. It's pornography with an absolute dead ringer celebrity face. There are no context clues -- physical SMT, celebrity references, video provenance, etc.

What do?

[tshaddox]

I mean, if you don’t know who is responsible, what do you ever do? What if you find a dead body but no clues about how they died? What’s uniquely tricky about this particular type of crime?

[a_wild_dandan]

There is no unique trickery here. In both cases, you do nothing -- don't charge presumed innocent people with "likeness" theft or with murder.