Critics of U.S. surveillance activities rallied Saturday in Washington, D.C. in a sign of growing furor over the practice.
The "Stop Watching Us" rally and march took place Saturday morning, the 12th anniversary of the signing of the Patriot Act.
The event came amid a diplomatic crisis prompted by allegations that the National Security Agency (NSA) tapped the phones of world leaders in a wide-ranging surveillance effort.
In response, U.S. allies in Europe are readying new international agreements that could potentially limit U.S. intelligence activities on European soil, according to reports.
Organizers of Saturday's rally predicted that thousands of supporters would join the march from Washington, D.C.'s Union Station to Capitol Hill.
The event followed a lobby day in which critics of NSA surveillance called on Congress to "rein in" the agency and conduct additional oversight of its activities.
"Right now the NSA is spying on everyone's personal communications, and it’s operating without any meaningful oversight," states a memo on the "Stop Watching Us" site.
The event was organized by a diverse coalition of groups, including the American Civil Liberties Union, FreedomWorks and Mozilla.