Anonymous person reported them because he is afraid of his or her own life. Also why only demanding for cryptocurrencies and not fiat? Privacy is very important.
https://cointelegraph.com/news/gang-members-sentenced-kidnapping-cryptocurrency-investor
You know they were afraid of their identity being revealed and there was no way the crypto guy would have to go make deposit in bank without them being tracked through their names, and even if they demanded for a transfer he would still run to bank to get their account monitored and they could easily pick them up without much delay. But what I don't actually like about this is that, same people attempted to have him send them crypto severally without the victim at least reporting immediately the first attempt was made, okay what if the anonymous person didn't sight them and get them reported meaning they could have forced out some valuable assets from him. I don't think if the guy really understand what security be or how important it's than allowing them to have their ways to him again.https://cointelegraph.com/news/gang-members-sentenced-kidnapping-cryptocurrency-investor
For security purposes I won't click on the link rather replying based what I read here
