There are a few things I've learned - or not learned - from releasing software.
1. People like to VENT. Some people are going to post nasty stuff even though they would normally act different in person.
2. Can you turn the nasty things into something positive? People vent because they are annoyed, or angry, or confused about something. Can that be fixed? Can that be improved? There may be a legitimate issue that could be improved even though they are not expressing themselves positively.
3. People vent because they care. They are invested enough in your software that they would like to see change.
4. For every person venting, there are probably 10x that are happy but just aren't commenting. Sometimes it seems that everybody is just unhappy, but really it's just the vocal minority.
5. Some people just need to be ignored.
6. We are not made for the Internet. It's going to be the downfall of civilization.
Our social structures and social instincts are made for small groups of people in a tribe, distrusting outsiders. The Internet can be great for humanity, but we're 200 years away from learning how to use it correctly.