Users of peer-to-peer file-sharing services may be sharing more than they bargained for, a former White House cybersecurity advisor warned last week.

Security researchers have found thousands of files with sensitive information by searching through file-sharing networks, said Howard Schmidt, chief executive officer at R&H Security Consulting. Schmidt, who has also worked as chief security officer for Microsoft, made the comments during an SDForum seminar in Palo Alto, California, last week.

Medical records, financial information, and router passwords have all popped up on P-to-P networks, often after users inadvertently share folders containing the data. People dont realize youre not just sharing your music, Schmidt said. Youre sharing your personal files.

Millions of U.S. households still use P-to-P services, though the practice of illegally downloading music from these services has been on the decline, according to the NPD Group research firm

And with all of those possible victims, criminals see an opportunity to search these networks for sensitive information, Schmidt said. These are real live search strings the bad guys are using: bank such-and-such statement for August, bank such-and-such May statement, account summaries, account stop payment, Internet scams, bank routing information, he said.