This or similar wording reported by news.com.au (Australia). Is totally fake of course.  I received this e-mail on 2/13/2018:
Hello,
If u were more careful while caress yourself, I wouldn't write dis message. I don't think that playing with yourself is extremely terrible, but when all your friends, relatives, сolleagues receive video record of it- it is undoubtedly [bad for u.

I placed virus on a web-site for adults which was visited by you. When the target click on a play button, device begins recording the screen and all cameras on your device begins working.

Moreover, my program makes a remote desktop supplied with! key logger function from your device , so I was able to get all contacts from your e-mail, messengers and other social networks. I've chosen dis e-mail cuz It's your working address, so u must check it.

I think that 390 usd is pretty enough for this little false. I made a split screen vid(records from screen (interesting category ) and camera ohh... its awful AF)

So its ur choice, if u want me to erase ur disgrace use my bitcoin wallеt аddress- (deleted)  
You have one day after opening my message, I put the special tracking pixel in it, so when you will open it I will know.If ya want me to show u the proofs, reply on this letter and I will send my creation to five contacts that I've got from ur device.

P.S. You are able to complain to cops, but I don't think that they can solve ur problem, the inquisition will last for several months- I'm f! rom Belarus - so I dgf lmao