I can't speak for US law but I'm pretty sure it is (it is in my country afaik). However, I can imagine it's close to impossible to execute if you don't know wh

I can't speak for US law but I'm pretty sure it is (it is in my country afaik). However, I can imagine it's close to impossible to execute if you don't know who posted the material or it has been reposted like in the article.