When I teach about social media, the single most debated topic from audience members is whether it is ok for an attorney to tell his clients to delete relevant posts. I have never once hesitated in my response; the answer is 100 percent no. Every judge with whom I have spoken, every ethics attorney with whom I have spoken has agreed with me.
It is very tempting, I am sure, to delete a post that you know can be harmful to your case, but then again, it is very tempting to destroy a letter or delete an email message that is harmful to your case. Neither one of these actions is ok either. Especially after you have been served with notice to preserve.
If you are concerned about information your client has already posted on a social media site, your best bet is to make sure the privacy settings for that site are as strong as possible. You should also advise your client to (a) stop posting on social media sites or at least (b) post nothing relevant to the case. You also need to advise your client not to delete anything he has already posted.
Don’t risk spoliation, an inference against your client, sanctions, or having a favorable verdict overturned. Treat social media evidence the same as you would any other evidence; follow the ethical, discovery and evidentiary rules.