Can one be really sued for libel in court for posts and tweets made online?

In this day and age, unfortunately that is really true. This can in fact happen, due to the fact that everyone is lawsuit happy these days and sue over the most minor infractions. It is really pathetic to say the very least but it can in fact happen very often. It is way too easy to sue someone these days and there are too many nonsense lawsuits. I think if someone gets offended by libel being posted on a social networking website, they really do have some priorities that are twisted. It is in fact the Internet, it was built on unfounded comments. Still with all the nuisance and nonsense lawsuits flying around the courts, the fact that there are not more cases of this happening, just surprise me.