Probably not the best from Biden, but also noticed the person who posted it changed what Biden said. If you listen he says, "literally incents blackmails or mortifies that person. Sends it out or puts it online"
It's still a bit of an odd comment and probably not entirely accurate, but he's not saying that everyone knows someone who blackmailed someone else. He's saying that everyone probably knows one person who has been involved in revenge porn. It was also backed up by the statistics they provided that said that 12% of Americans between 18-29 had been the victim of revenge porn with someone posting naked photos of them online or blackmailing them.
Straight after that he said, "We're giving survivors real resources against abuse now", because that's what the speech was for. They're putting in more protections for people how have been the victim of revenge porn.