PayPal has admitted that the US Government was behind the company's decision to sever ties with whistle-blower site Wikileaks. Meanwhile, hackers who forced down the website of the international credit card service MasterCard on Wednesday warned PayPal that their site would be down in a few hours.

At the Le Web conference in Paris, PayPal vice president Osama Bedier told TechCrunch that the company is bound to comply with regulations worldwide.

The (U.S.) State Department told us these were illegal activities. It was straightforward, he said.

Twitter messages posted by reporters suggest that the response was greeted with boos from the audience.

We first comply with regulations around the world making sure that we protect our brand, the VP added.

Hackers forced down the website of international credit card company MasterCard earlier today. The move is likely to be revenge by alleged Wikileaks supporters. In what they called Operation: Payback, the anonymous hackers announced on Twitter that they successfully brought down the MasterCard website. MasterCard had earlier severed ties with the whistle-blower site, suspending all payments to the organization.

MasterCard's website is currently inaccessible.

Operation: Payback  threatened PayPal that their site would be down in the next couple of hours.

We will fire at anyone or anything that tries to censor Wikileaks, including multi-billion dollar companies such as PayPal, a message posted by the group, Anon_Operation, said.

Responding to the threats, Bedier maintained, One of the signs that you're a successful payments company is that hackers start to target you. This case isn't anything different.

Anon_Operation also warned Twitter for its censorship on Wikileaks messages.

Twitter, you're next for censoring Wikileaks discussion, it said on Wednesday.