Hey, @Karunya, not only green hat world but there are many (1000s) of pirated and illegal sites using Adsense. I don't know what is the main reason behind this, but it is clear that they approve these sites to earn more.
As these types of sites get thousands and lakhs of views per month and accepting them will increase Google's revenue, so they approve them.
I think that this is the main reason for this.
Hope this helps