1. Track down the people sending this information and prosecute, convict and jail them (at a minimum)
2. NEVER NEVER NEVER open a video sent by anyone to you over facebook or other social media. If they want you to see it then they should post it publicly.
3. NEVER NEVER NEVER give out your personal email. That should be restricted to family and closest friends.
4. All videos etc that come to your public email should immediately go to the trash bin.
Why give anyone the opportunity to infect your computer or your mind.
In my line of work that is not an option. Have to be accessible to potential clients, and my business email address feeds in to my personal one anyway.