The music sheets the site provides are not the official ones nor are the pieces-songs (call it whatever you like) played. Is it illegal to upload your personal "cover" of a song-piece since it is for free? Same thing is happening in youtube but none mentioned it. I would like to see evidence instead of "You know i don't like it, (he obviously won't know the law restrictions) it's illegal so stop it." behaviors. Thats for the copyright section.
I totally disagree that it is some kind of "teaching" and i think it is posted at wrong section. This website does not teach you, unless showing the construction of the chords (not fingering etc. included) is considered teaching. It simply gives you a visual clue of how the piece-song can be (badly) played and give you the sheet (mostly beginner level) and lyrics to learn it yourself.
I give the site thumbs up. I have abandoned playing piano (was playing for 2 years) 4 years ago and a recent try to start over again failed. I prefer to take a piece-song that i like for ex. a Chopin etude and struggle to learn it, than learn hundreds of technical pieces, which most of them i won't like, to be able to learn fairly easily the deserved piece-song in a couple of years. Not to mention the money spent on lessons (i know it hurts for you but thats the truth).
Someone who hasn't good piano skills (beginner) and wants to learn to play his desired song-pieces will find a very helpful website.
Someone who wants good fingering, proper technique and metronome like beat or whatever, better search for something else.
The site does almost what it says: "There are millions of pianists out there that took theoretical lessons when they were young, and
are looking for a cool new way to learn how to play their favorite songs without paying a lot of money for teachers.We have created the perfect tool for Pianists of all levels, encompassing the biggest index of piano tutorials, all animated, classified according to your favorite artists, proffered music genre or playing level"
almost...: "OnlinePianist was born out of the ever increasing need for free online
piano lessons and tutorials."
For clarification, i have read all the previous messages and know what to expect compared to the author of this thread, i have no more further benefit/connection from/to the site than that as a simple internet user.
onlinepianist you did a good job!

P.s. Excuse my long post!