U.S. Capitol Police arrested Wednesday a former Democratic staffer suspected of posting the personal information of at least one United States senator to the internet. Jackson A. Cosko, 27, was charged with making public restricted personal information, witness tampering, threats in interstate communications, unauthorized access of a government computer, identity theft, second-degree burglary and unlawful entry, according to a Capitol Police statement. Cosko is a “Democratic Political Professional & Cybersecurity Graduate Student,” according to his LinkedIn page, which states that his job duties in the U.S.