The founder of Swiss Bank Post Finance, Mr. Julian Assange, had closed the account of WikiLeaks. Hackers also attacked PayPal, but only managed to take down its blog, while its services are still working.
The spokesman of the hacker's group that attacked on Post Finance & PayPal says that they will hack any website which is going to bow down to Government pressure. The same group is allegedly behind the series of attacks popularly known as "Mission: Payback" and targeted anti-piracy organizations RIAA & MPAA .
Companies such as EveryDNS.net & Amazon which have denied service to WikiLeaks claims that they hadn't closed their WikilLeak's account due to any political pressure but due to technical or procedural reasons.
A very famous site MasterCard has also been taken down by hackers as it also denied service to WikiLeaks.