Using this site against you?

I spend a lot of free time on this site, and I can't help but notice the amount of incriminating evidence people provide on this site. Amongst that a lot of people post racial and hate post that can be consider illegal or offensive. My question is can the law use these post against people in court. A computer is about a secure as a wet paper bag, especially the internet. Are sites like this used to extract information, and possible incriminate a person. I have seen people as much as admit guilt, so could that information be used as evidence. I found this thought as interesting, how bout you. Could post that display hate be used to charge a person with ault or maybe even a hate crime? Just a random question, what do you think.