See the fact sheet for the details:

Fighting Internet Piracy

• The United States and Russia agreed on the objective of shutting down websites that permit
  illegal distribution of music and other copyright works. The agreement names the Russia-based website allofmp3.com as an example of such a website.

Allofmp3.com's position was that they were authorized to sell in Russia, and that they, therefore, could sell online to anyone. It always seemed a stretch.

The USTR acting, though, and specifically naming this one site -- which must be bigger than I thought -- is evidence of the power of the recording industry. I'm sure there was a feeling that it needed to be nipped in the bud before people have bandwidth that would make widespread video distribution from foreign locales just as prevalent.

It will be interesting to see where they move to.