TL;DR - Mining coins to solve captchas

I was puzzled when I clicked to download something and this little captcha thingy appeared. I clicked, as usual, to solve it, but was amazed to look just a progess bar going and going... then I saw a little legend that says "what's this?", click and this is the link

https://coinhive.com/info/...

Practically, you're mining Monero instead of watching ads and solving regular captchas...

What are your thoughts on this?