Paul may be protected by the speech and debate clause but there are two big reasons why no social media should be helping this.
1. It is clearly intended to harass and threaten the whistleblower and anyone else who these trolls might choose to claim is the whistleblower.
2. What is known is that the whistleblower is an intelligence officer, that the source of the leaks of the person's name had to have come from a person who had signed an NDA to keep government secrets and vis a vis Valerie Plame, it is a Federal crime for someone with that knowledge to reveal the identity of the an intelligence officer in some situations.
Social media sites should not facilitate either of these crimes.