After disappearing for a couple of weeks, the hacker "Guccifer 2.0" returned late this afternoon to provide a new headache for Democrats.

In a post to his WordPress blog, the vandal--who previously provided nearly 20,000 Democratic National Committee e-mails to Wikileaks--uploaded an Excel file that includes the cell phone numbers and private e-mail addresses of nearly every Democratic member of the House of Representatives.

The Excel file also includes similar contact information for hundreds of congressional staff members (chiefs of staff, press secretaries, legislative directors, schedulers) and campaign personnel.

In announcing the leak of the document, "Guccifer 2.0" reported that the spreadsheet was stolen during a hack of the Democratic Congressional Campaign Committee. "As you see I wasn't wasting my time! It was even easier than in the case of the DNC breach," the hacker wrote.