What you say at an accident scene can be used as evidence later. That makes sense. When someone says, "Boy, I should not have had that last beer! It really hit me hard," that statement can use used later at trial.
Today, people are making a lot of statements, and making them very publicly. People use social media sites like Facebook, Twitter and Instagram frequently. Posting after a car accident can impact a personal injury claim.
Insurance companies and their army of lawyers commonly use investigators, medical researchers and computer database indexes to investigate claims. They use these tools to look for fraud occasionally, but their primary use is to minimize claims. Social media has become a new tool to investigate those claims.
Social media posts, in my observation, tend to make one's life seem positive. Accomplishments, trips, and happy family events are usually shown, along with obnoxious pictures of food at dinner and silly cat photos. However, that photograph showing how heroic you were shoveling the neighbor's driveway can be used later to show how that neck sprain wasn't that bad. The picture and caption don't show how much pain you were in later that evening, nor that the walkway was shoveled for the elderly neighbor that just came home after suffering a stroke. At trial, however, or during claim negotiation, the photo looks like you were not hurt that bad.
Similarly, posting "I'm going to Court today with my lawyer. Big $$ for me" is a bad idea. Jurors commonly look at social media during breaks. Despite the Court instructions not to do this, I have been told that it happens regularly by bailiffs and court reporters. This type of post makes a victim look like a jerk. (Sorry, but true.)
Even when set to private, Facebook postings can be discovered in litigation. So, my advice is simply not to post to social media while a personal injury claim is pending. Yes, the world may miss out on your family photos, but you won't give the insurance company any "statements to be used against you later."