By Brendan Sasso

The Supreme Court on Tuesday blocked a lawsuit challenging the federal government’s monitoring of international phone calls and emails.

In a 5-4 decision that split along ideological lines, the court ruled that activists, journalists and lawyers represented by the American Civil Liberties Union (ACLU) could not prove that they were harmed by the wiretapping program.

“Simply put, respondents can only speculate as to how the attorney general and the director of national intelligence will exercise their discretion in determining which communications to target,” Justice Samuel Alito wrote for the majority, agreeing with the Obama administration’s position that the challengers lacked the legal standing to sue.

Rochelle Bobroff, an attorney for the Constitutional Accountability Center, a liberal advocacy group, said that the decision results in a catch-22 for anyone trying to challenge the program.

“The government wouldn’t tell anybody whether they were under surveillance so no one could prove whether they were under surveillance,” she said in an interview. “It’s very, very unlikely that this will ever be challenged, and that didn’t seem to bother the majority at all.”