Speaking before a senatorial subcommittee on Wednesday, the intelligence community’s top lawyer told senators that the National Security Agency is incapable of knowing how often Americans’ data is captured inadvertently. Robert Litt, general counsel at the Office of the Director of National Intelligence, told the Senate Judiciary Subcommittee on Privacy the problem is that it would be “very resource-intensive” to figure out whether foreign targets are communicating with Americans, according to The Hill.

While Americans theoretically have protection from intrusive government searches under the Fourth Amendment, foreigners certainly do not. And Litt noted that determining that " second hop " person’s nationality would “perversely require a greater invasion of that person’s privacy.”

However, Sen. Al Franken (D-MN), who chairs the committee, suggested that it would be possible “through statistical sampling.”

“Isn’t it a bad thing that the NSA doesn’t even have a rough sense of how many Americans have had their information collected under a law… that specifically prohibits targeting Americans?” Franken asked.

The junior senator from Minnesota is the author of the Surveillance Transparency Act of 2013, a bill that would allow companies to report on the number of government requests they receive. That's a right many companies are currently fighting for before the Foreign Intelligence Surveillance Court.