I recently posted comments about my past employer on fb,

I recently posted comments on fb about my past employer, which were not demeaning or profane, they are threating to take action,, what action can they take? The comments were about a verbal agreement we had.

all I can say is perhaps you should have not directly mentioned your employers name or been a little more evasive about the case but most important always understand when you put anything on this internet there is a great possibility the people or person you don't want to read it will or someone who will know who you are talking about. if you are in a litigation against an employer you should never tell anyone outside of a trusted relative or friend . definitely not the internet with strangers.