If you have a little discernment you can probably filter out bad advice. Personally I have often gotten better advice about legal or health issues from online forums than I have received from professionals like lawyers and doctors. At a minimum these responses are a cheap way to learn about things you should be looking into so you are better prepared for talking to a professional person.

If you talk to _your_ lawyer about your issue the lawyer can't go and tell anyone else, nor can that discussion be raised as part of a legal process against you. Not the case if you post it to a public forum.