Report them using the in-game reporting feature if there is one, faling that use the link below, although it'll take you a while to report 250 people!
More than likely they are laughable wannabe hackers trying to hack the PSN all over again like the April 20, 2011 outage which won't happen again because there are other people going to report them. Blackmailing 250 hackers won't do anything good. Best bet is to report the ringleader of the masses, nascar12345678.
Customer Service - 1-800-345-7669
Account and Billing Support - 1-877-971-7669