If you weren't wary of MacKeeper before, you have reason to be now. This week, white-hat security researcher Chris Vickery posted on Reddit that he was able to easily find and download account details of more than 13 million MacKeeper users by searching for open database servers. Kromtech, the maker of MacKeeper, worked with Vickery to close the data exposure.

Following the news, Kromach said it has taken steps to safeguard user data, including implementing new security measures and resetting user passwords.

Mac users have had an uneasy relationship with MacKeeper. They've been frustrated by its intrusive popup ads, suspicious of its claimed benefits, and flummoxed by how hard the app is to uninstall.

Clifford Colby follows the Mac and Android markets for Download.com. He's been an editor at Peachpit Press and a handful of now-dead computer magazines, including MacWeek, MacUser, and Corporate Computing.