House Speaker Nancy Pelosi, D-Calif., had a laptop stolen, as did Sen. Jeff Merkley, D-Ore., who tweeted about the theft.

It wasn’t immediately clear what protections were on those devices, though Congress generally lags behind the federal government in implementing cybersecurity measures. Not all Senate computers automatically encrypt their hard drives or require a password to log in if they’re unused for a few minutes. Emails were visible on a desktop computer left running in Pelosi’s office.

While experts say most congressional laptops shouldn’t provide easy access to classified material, both the Senate and House connect to a centralized email server, and staffers’ computers likely contain months or years of emails and other sensitive material.

“There’s a very good chance that a lot of sensitive and possibly secret information could have been leaked by those people being in there and taking stuff,” said Lou Rabon, the CEO of Cyber Defense Group, a cybersecurity consultancy based in Los Angeles.