Thus ends this round: Facing growing public pressure from civil liberties advocates, federal prosecutors on Tuesday dropped subpoenas that they issued last week ordering antiwar protesters to appear before a grand jury and ordering a university to turn over information about the protesters. The protesters, who had said they feared that the unusual federal inquiry was intended to silence and scare people who disagreed with government positions, declared victory. "We made them want to stop," Brian Terrell, executive director of the Catholic Peace Ministry here and one of four protesters who received subpoenas, told a crowd at the federal courthouse. "We're here to make them want to never let it happen again."