Earlier quoted context omitted.
Why would it be YouTube’s job? Someone has claimed ownership and is now making profit on it - that (to me a non lawyer expect same behavior from the legal system ;) ) seems like it would be a standard copyright violation :D
If YouTube is unwilling to pass along the information, as the parent says, then who are you going to file suit against? You’ll have to sue an unknown person and get a court order to get YouTube to turn over the person’s name. That’s an expensive start to aprocess with an unknown end. Isn’t it even possible the person isn’t in the US? Then you’ve thrown away your money.
Filing a simple John Doe summons in your home jurisdiction and then sending a subpoena to YouTube for the offending contact information is pretty trivial. You could probably find someone to do it for you for a thousand bucks or less.
Admittedly that’s not free but in a context like this with real money at stake it’s not a huge obstacle.