Facebook Busted You and You Probably Do Not Know It

  How your ex will know if you've been stalking their Facebook: Embarrassing glitch exposes snoopers - how to see if you've been busted

"'We fixed a bug related to a recent app update that caused some Facebook friend requests to be sent mistakenly,' the spokesperson said. ...if you're still worried you've been affected by the technical defect, head to facebook.com/friends. From here, click 'Friend Requests' in the left-hand tab followed by 'View send requests' to review the pending requests. ..."

Reference: www.dailymail.co.uk