In May 2012, Facebook introduced a feature displaying when a friend has read a message you sent her/him in the chat. This indicator is shown without the consent of your correspondent, who is not informed that you see it. Many are considering this as an infringement to privacy.

This userstyle hides every “Seen hh:mm” from the chat box, a nice thing to do if you respect your friends' privacy. Warning: it will not prevent your friends from seeing when you've read their messages, but only prevents you from seeing when they've read your messages.