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.