The group that claimed responsibility for last week's PBS website hack has claimed it is hacking Sony right now  and stealing "internal" information.

"Hey @Sony, you know we're making off with a bunch of your internal stuff right now and you haven't even noticed? Slow and steady, guys" reads a tweet published by the hackers this morning.

LulzSec, as the group is known, threatened Sony with what it describes as an "operation".

"This is the beginning of the end for Sony," it said on Twitter.

Then, "(Sony + Ownage) Phase 1 will begin within the next day. We may have a pre-game show for you folks though. Stay tuned."

LulzSec has already hacked the PBS website, posting a report that deceased rapper Tupac Shakur is "alive and well" in New Zealand, along with Biggie Smalls, aka The Notorious BIG.

It is also reportedly responsible for the hacks on Sony BMG's Japanese website.

Sony said this morning that it will fully restore PlayStation Network services by the end of the week.

Sony took PSN offline on 20th April following a hack that saw personal information tied to 77 million accounts compromised.

Sony is working with the FBI to track down those responsible.