[cbs]

>You are first going to have to contact Pinterest to get the information of the user who has listed this said work. Are Pinterest goijng to give up this information so willingly? Probably not...

IIRC, in this case you sue John Doe and have the court compel Pinterest to identify him.

[pavel_lishin]

Does pinterest require identifying information in order to register?

[girlvinyl]

It requires a facebook or twitter login. Plus it should have some kind of IP log somewhere. Pinterest won't have the entire identity, but this is how e-discovery works. You keep sending subpoenas up the hierarchy until you get to the ISP. The ISP provides the subscriber information.