On the other hand, do you think those guys are really victim?
It is possible that someone may have sent their assets with the intention of doubling them.
I have a thought that possibly these bitcoins sent were part or accomplice of the scammer?
Probably can't say for sure.
But its always good to report all kind of scam here. 0.1 to 0.2 btc is like 100% profit without having sweat is purely scam.
Yes, It is necessary that people should be warned about every scam so that they can protect themselves from such threats.