... and ignored requests to take down infringing material ...
Bullshit there. Megaupload removed every link to infringing material where notice was given that it was infringing copyright in accordance with the DMCA. They were in fact very careful to comply with the DMCA. What they didn't do was remove links to the same material that weren't in the notice.
Megaupload hashed every file and if more than one person uploaded the same file, they only stored it once and linked both accounts to the same file. So their approach makes sense - if Peter and Paul both upload the same file and Peter is violating copyright it doesn't mean Paul is also (he may even be the creator.)
In real life of course there are often many violators posting the same file, and Megaupload were well aware that piracy was a huge driver of their success. Nevertheless, your statement is factually incorrect.