Is it true that Prince was forced to shut down the NPGMC site because someone sued him? Were there copyright issues and was Prince the victim that time, forcing him to close down that site and look for another catchy title, 3121?

If true, I think I can understand Prince's recent moves. He's just paying back in kind, and he is still hurt as hell. Sue me, would you? Take this: It doesn't matter to him now who he runs over.

But is it true?

There was a dispute over "NPG", and the site closed shortly thereafter.

What I found odd is that the lawsuit happened recently, as he's been using NPG for what, 16-17 years now?

Se7en said:

The legal papers appeared to originate from a dispute over using 'NPG' in connection with printed material.

As I understand it, the Nature Publishing Group was challenging the use of NPG, given that their main object as an organisation is to publish books. Prior to the issue of 'Prince in Hawaii' copyrighted to NPG Records and published by the NPG Music Club, Prince's use of the NPG logo and trademark had largely been associated with music releases. Organisations are very protective of brand and logo, and will seek to defend its association solely with their own products.