We already knew U.S. voting systems had security flaws ? the federal government put that nail in the coffin when it repeatedly confirmed that Russian hackers breached systems in at least 21 states during the election last year.

But on Friday, hackers stateside showed us just how easily some of the electronic voting machines can be cracked. 

Those who attended DEF CON, a 25-year-old hacking convention held in Las Vegas, were given physical and remote access to voting machines procured from eBay and government auctions.

Within about 90 minutes, they’d exploited weak and outdated security measures to gain full access, The Register first reported. Some physically broke down the machines to reveal their vulnerabilities, while others gained remote access or showed that external ports found on some could be used to upload malicious software.