it worked for youtube/google

You mean the same youtube where the Viacom sued them for videos uploaded by employees of Viacom [1]?

[1] http://consumerist.com/2010/03/viacom-youtube-throw-legal-pu...

... and Google bought them and made the team millions of dollars? Yeah, that YouTube.

Yes, the same Youtube that sold for $1.65 billion several years before an unsuccessful lawsuit.

How is that relevant?

It's the whole principle behind DMCA, isn't it?

I don't think the DMCA envisioned hosting providers that are specifically designed for infringement.

> I don't think the DMCA envisioned hosting providers that are specifically designed for infringement.

In order to keep their immunity, an online service provider must "not receive a financial benefit directly attributable to the infringing activity." The provision clearly targets hosting providers that are designed for infringement, indicating that they did envision that.