"Some credit cards were stolen during breach of company X; to see if your card was stolen, please enter your card number, CCV and zip code!"

NEVER give your password to a third party; the only safe recourse is to change the LinkedIn password immediately, and if you used the same password elsewhere (tsk, tsk) change it there as well.

A compromise is known to have occurred - the only safe operating assumption is that all password hashes were obtained.