Day 12 speaks of the Betraying Tongue.
This person does more than gossip -- this person spills a confidence and does it with a malevolent purpose.
I've not been around many people who do this, probably because I am not in the workplace. The only place I've experienced it was when I was in the law business. I don't miss either being on the receiving end or being tempted to join in ascribing it to being "part of the game."
One of the guiding principles of our Community Bible Study group is that it is a safe place for people to share their concerns and worries, and that information is kept confidential. The joy of that is that people can be transparent and open and really start to heal from some pretty icky things. It only works because we all agree to that. This is the most unique group I've ever been involved with in this way. And it all revolves around prayer.
If you know someone like this, you should be praying for them. But keep your distance as well.