Sources report that Facebook is testing out the hashtags currently, and is considering adding the categorizing feature to its site as well.
If you don't know what hastags are, currently users on Twitter, Instagram and Google+ can add a '#' symbol, or a hastag, before words and phrases. The hashtag turns the word or phrase into a link that leads to all other uses of that word or phrase.
One study that was done Twitter follower predictions found that the "overuse of hashtags" will "significantly reduce follower gain" on the social network.
