Yes, social media can be used in any court case: it is considered an admission by a party (e.g. something that the defendant said or wrote, etc.) and so is an exception to the hearsay rule that normally bars most out-of-court declarations or statements--that is, it it admissible as evidence.Of course, you have to remember that you are not in charge or control of the case: the prosecutor is. You cannot use this in the traffic court case: only the prosecutor can. All you can and should do is bring this to the prosecutor's attention, for him/her to use if he/she wants.