“Chilling” is the word lawyers use to describe governmental behavior that does not directly interfere with constitutionally protected freedoms, but rather tends to deter folks from exercising them.
Classic examples of “chilling” occurred in the 1970s, when FBI agents and U.S. Army soldiers, in business suits with badges displayed or in full uniform, showed up at anti-war rallies and proceeded to photograph and tape-record protesters. When an umbrella group of protesters sued the government, the Supreme Court dismissed the case, ruling that the protesters lacked standing — meaning, because they could not show that they were actually harmed, they could not invoke the federal courts for redress.
Yet they were harmed, and the government knew it. Years after he died, longtime FBI boss J. Edgar Hoover was quoted boasting of the success of this program. The harm existed in the pause or second thoughts that protesters gave to their contemplated behavior because they knew the feds would be in their faces — figuratively and literally. The government’s goal, and its limited success, was to deter dissent without actually interfering with it. Even the government recognized that physical interference with and legal prosecutions of pure speech are prohibited by the First Amendment. Eventually, when this was exposed as part of a huge government plot to stifle dissent, known as COINTELPRO, the government stopped doing it.