A former staffer who worked for several Democratic lawmakers, including Senator Dianne Feinstein and Rep. Sheila Jackson Lee, was arrested by U.S. Capitol Police and charged with several felonies relating to a "doxxing" incident that exposed the personal information of several Republicans online.

U.S. Capitol Police said 27-year-old Jackson Cosko was charged with making public restricted personal information, witness tampering, threats in interstate communication, unauthorized access of a government computer, identity theft, second-degree burglary and unlawful entry. Police added that the investigation was continuing and more charges could be filed. Senior congressional sources tell Fox News that Cosko most recently worked as an unpaid intern for Rep. Sheila Jackson Lee, D-Texas. He previously worked with Sen. Maggie Hassan, D-N.H., and former Democratic Sen. Barbara Boxer of California. He also worked or interned with the office of Sen. Dianne Feinstein, D-Calif., the ranking member of the Senate Judiciary Committee, as well as with at least one other unnamed lawmaker. A LinkedIn page with Cosko's name on it describes him as a "Democratic Political Professional & Cybersecurity Graduate Student." Jackson Lee's office told Fox News that Cosko had only worked there for a couple of months, but has now been terminated.

Cosko is one of those perpetual grad students who never seems to get his advanced degree. Usually, these permanent students keep changing their academic discipline and stay in school virtually forever.

How did Cosko get access to these computers? This is fishy.

Sources tell Fox News that authorities are looking into the possibility that at least two other senators were doxxed. Fox News has also learned that Cosko was discovered by aides Tuesday night working on a computer in a Capitol Hill office that did not belong to Jackson Lee. He was arrested at his Washington home the following day. Capitol Hill security officials plan to scrub the computers in question.

Somehow, I can't believe that security is so lax that Cosko could waltz into an office and start using a computer that didn't belong to him. This is an incident that bears close investigation. Before security officials "scrub" those computers, it might be helpful to discover what the hell Cosko was working on when he was caught.

The doxxing incident may be seen as a minor annoyance. The personal info of Republicans was on Wikipedia for only a few hours, and there doesn't appear to be any threat to the safety of members or their families.

But I will bet that Cosko had his fingers in a lot of cyber-operations. Whether he was directed to do so by staffers or members is a question that needs to be answered.