Webcam blackmail happens when a cyber crook threatens to spread a private video unless he receives money rapidly.
1- Do not answer to the cyber crook
2- Lock your accounts on the social networks
3- Take screenshots of the threats
5- Confide in a trustful person
6- Inform your friends about the scam attempt
7- In case of web broadcast of the embarrassing content:
– ask the host site for its deletion
– and the web search engines for its unreferencing.
For more information (in French) you may get to the French National Commission on information technology and liberties (CNIL) website