The BBC has a story on the law that the Russian Wikipedia community protested:
If the websites themselves cannot be shut down, internet service providers (ISPs) and web hosting companies can be forced to block access to the offending material.
The list of banned website will be managed by Roskomnadzor (Russia's Federal Service for Supervision in Telecommunications, Information Technology and Mass Communications). It is meant to be updated daily, but its contents are not available to the general public.