"Deleting" a comment doesn't get rid of anything

The article here talks about how a Philadelphia Eagles employee, Dan Leone, got fired due to posting a very opinionated comment on Facebook. He posted,  "Dan is [expletive] devastated about Dawkins signing with Denver ... Dam Eagles R [expletive]!!" Now is this simply freedom of speech or should Leone have known better? He was voicing his opinion to his fellow "friends" on Facebook, and within hours, everyone in the sports world was aware of what happened. Leone knew he did something wrong and he "deleted" the comment, but that did not get rid of anything. There were traces of what he said everywhere - screenshots, videos, and people had already seen it. Leone lost his job over one little comment, but he should have realized what he was doing with these types of stories being more popular. Next time you post anything online, make sure you understand that its going to be online for as long as you live and it may come back to haunt you. Digital citizenship is important.