The BBC's Jonny Dymond says that with Mr Rubio and Mr Blunt withdrawing their support, the Senate bill - Protect Intellectual Property Act (Pipa) - that had looked likely to pass, now appears to be in trouble.

Protect Intellectual Property Act (PIPA)

It is not possible to break down figures spent lobbying specifically on the Stop Online Piracy Act (Sopa) and Protect Intellectual Property Act (Pipa) anti-piracy bills.

The legislation in question, Sopa (Stop Online Piracy Act) and Pipa (Protect Intellectual Property Act) is still a long way from making it into law, particularly since the White House expressed some serious reservations.

Wikipedia, which attracts millions of hits every day, is opposed to the US Stop Online Piracy Act (Sopa) and Protect Intellectual Property Act (Pipa) being debated by Congress.