No one is claiming responsibility for a hoax press release claiming that the U.S. Chamber of Commerce had changed its position on climate change legislation.The release, which was sent out Monday, said that in a dramatic shift, the chamber was supporting the House cap-and-trade bill. The chamber has been aggressively lobbying against the House bill, arguing that any climate change bill must include commitments from countries such as China and India to cap carbon emissions.Reuters reported the policy change before updating the story to acknowledge the hoax.Chamber spokesman J.P. Fielder said the release absolutely was not put out by the business trade group, which is still opposed to the House climate change bill. So far, no organization has come forward to claim responsibility for the release. Tyson Slocum of Public Citizen said he doubts that any mainstream environmental group is behind it.The chambers been attracting enough bad publicity of its own, Slocum said. The chamber went from being on the offensive from trying to stop efforts on climate change to being on the defensive with groups dropping out.A handful of chamber members quit the group over its stance on the climate bill.