Thousands of contributions to Democratic presidential candidate Bernie Sanders' campaign in January violated federal campaign finance laws, election regulators said on Thursday. The Federal Election Commission sent a letter to the Democratic presidential candidate's campaign committee on Thursday with a 90-page spreadsheet listing 3,457 "excessive, prohibited, and impermissible contributions." The campaign's January financial disclosure filing listed contributions from foreign nationals and unregistered political committees, the FEC said. Other contributions came from donors who exceeded the $2,700 per-election limit.