The US National Security Agency's recently revealed internet surveillance program PRISM has been broadly condemned by tech companies, even those whose networks were allegedly involved. But now some organizations and companies are going further, sending a letter to Congress today calling upon lawmakers to immediately halt PRISM and other forms of internet surveillance. Mozilla, Reddit, 4chan, the ACLU and the Electronic Frontier Foundation are among the 86 different organizations that have co-signed the letter, and they have also launched a new campaign online, "StopWatching.us," which invites web users to add their signatures to the petition as well.

If the move sounds a bit like the great online SOPA/PIPA protests of early 2012, that's by design. As Mozilla's privacy and public policy officer Alex Fowler wrote in a blog post today announcing the effort: "We need to rekindle that energy more than ever so our elected officials take the necessary actions to illuminate how current surveillance policies are being implemented." The campaign was coordinated in part by liberal advocacy group Free Press, which is holding a press call today at 1PM ET to elaborate on the campaign.

Update: Stopwatching.us plans to expand its protest to lawmakers' phone lines. "The next thing we need to do is have a call day where people pick up the phones and call Washington," said Rainey Reitman, activism director with the EFF, during Stopwatching.us's conference call with reporters this afternoon. "It's extremely unfortunate, but the thousands and thousands of emails [that Stopwatching.us is sending to Congress today] may fall upon deaf inboxes." Reitman didn't specify when the call day would take place, but said users could follow along by signing up on the Stopwatching.us website. Reitman was joined on the call by Mozilla's chief privacy officer Alex Fowler, who said that Mozilla would be using its default Firefox browser homepage today to send a message to users encouraging them to join in the protest.