Silverlight - Preventing the build of localized dll's

When you build a Silverlight (4) project, the Bin folder get filled up with localized versions of the dll's referenced in the projects where these localized versions exist.
It turns out they are found here:

C:\Program Files (x86)\Microsoft SDKs\Silverlight\v4.0\Libraries\Client

I suppose it's a nice feature in some cases, but it rather annoyed me, so I wanted to get rid of them. So I deleted all the localized sub folders in the SDK (de, fr, za-Hans, etc.) and yes!, at the next build localized dll's were no longer generated.