I use facebook for work and my writing, but different folks use it for different reasons; playing those online games, keeping up with family, posting naked drunken pictures or alerting devoted followers to political news.
I"m not sure why people would post pictures of themselves in compromising situations, I'm also shocked at times by what folks SAY on facebook, it's a public forum and that **** never goes away.
Do what you think is right, what brings you the most peace. Those folks shouldn't upset you, they're just doing their lives and if it upsets you, off with their heads!