For one day last month, the English-language pages of Wikipedia went dark. The blackout of that site and an estimated 7,000 others was in protest against the Stop Online Piracy Act (SOPA), on the slate in the US Congress. Days later, the consideration of the bill in its present form was halted, and a vote on the related Protect IP Act (PIPA) postponed.

The protest and public outcry at the prospect of web 'censorship' was unprecedented. But the Obama administration had already voiced its disapproval in a White House statement refusing support for legislation that “reduces freedom of expression, increases cybersecurity risks or undermines the dynamic, innovative global Internet.” And in a debate ahead of last month's contentious South Carolina primary, all four candidates for the Republican presidential nomination came out against the acts.

The Research Works Act, introduced in Congress in December 2011, is also causing concern among scientists and the library community. Nature Publishing Group, to which Nature Physics belongs, does not support SOPA, PIPA or the Research Works Act — statements on its position can be found at http://www.nature.com/npg_/press_room/index.html.