Syanjali are you seriously asking me that question? Are you saying you didn't see nothing wrong (legally) with the question posted? Even Riten acknowledged that it is illegal.

Most textbooks are copyright protected. There are very few who release the copyright burden to scholars and teachers unless it is for monetary benefit, however most restrict you from even copying it. As such, making copies of the entire text book is ILLEGAL! Some sites upload those books w/o writer/publisher’s permission and that is infringement of copyright law.
To ask us about these illegal site is..well..illegal. Comprende Amigo?