Some kind of proof? I've heard many such stories about feminists receiving death/rape/etc. threats and it turned out as a scam to gain attention.
Those threats were real enough to convict at least two people in criminal court.
There are very many similar examples.
> Two people were jailed on Friday for subjecting feminist campaigner Caroline Criado-Perez to abuse on Twitter.
> Isabella Sorley was jailed for 12 weeks at Westminster magistrates' court. Co-defendant John Nimmo was jailed for eight weeks.
> Judge Howard Riddle said it was "hard to imagine more extreme threats".
> He said that, despite the defendants' claims, the harm threatened against Criado-Perez "must have been intended to be very high".