The most prominent activist group formed in the wake of the National Security Agency (NSA) spying revelations, StopWatching.Us, has reached half a million supporters. On a call with reporters today, the group discussed its future plans, which include rallies in 90 cities around the country for the July 4th holiday.

While hundreds of thousands of Internet users around the world have signed the StopWatching.Us petition, the movement is still at an early stage in terms of actually getting laws changed. Josh Levy of Free Press said the group is arranging dozens of meetings with constituents concerned about spying and their lawmakers. The focus is on changing Section 215 of the Patriot Act, which is believed to be the legal justification for the dragnet government surveillance uncovered by recent NSA leaks.

"We've seen authors of the Patriot Act say that section 215 is being interpreted in a way that they never anticipated," said Rainey Reitman, activism director for the Electronic Frontier Foundation (EFF).

There are a variety of bills that have been introduced, and the EFF is still analyzing them, Rainey said. Any change in Congress is going to take a long time. While there are a few dissidents, like Sen. Ron Wyden (D-OR) and Sen. Mark Udall (D-CO), they have historically not been the majority. The head of the NSA, Gen. Keith Alexander, was warmly received last month when he defended surveillance programs to a House committee.

The rallies are being organized by Restore the Fourth, a group formed last month in the wake of the NSA leaks. The organization aims to strengthen the Fourth Amendment protections against illegal searches.

Mozilla has been a key supporter of the coalition, and the company's VP of legal affairs, Harvey Anderson, was on the call today.

"More than 500,000 people have joined in less than three weeks," Anderson said. "I think that's pretty amazing and shows the concern people have. This kind of [surveillance] activity undermines the trust in what an open Internet can and should be."