There was a debate in Finland when the child porn filter was introduced a few years back. One guy had a website where he kept database of sites which were blocked but did not contain any child porn. Aftermath was that the site was added to list and that raised even more questions about the whole censorship idea. (http://en.wikipedia.org/wiki/Lapsiporno.info)
Unlike in Britain, the consumers did not have an option to opt out from the filter although it seems that majority of ISPs don't use it. Later on ISPs were forced to block piratebay.org and there have been discussions about blocking online poker sites etc, because Veikkaus enjoys monopoly in gambling and betting business in Finland.
Britain already has a mostly mandatory filter designed to save it from child pornography. Cleanfeed is run by the Internet Watch Foundation who look for images of abuse and put it on the blocklist. They're responsible for blocking Wikipedia due to an album cover.
The same filter is now used to action on high court demands to block torrent websites like The Pirate Bay.
Aha! Another great business opportunity reveals itself!
If you built a relationship with the filter provider, you could get companies to pay you to have their competitor's websites added to to the list of blocked websites!
Unlike in Britain, the consumers did not have an option to opt out from the filter although it seems that majority of ISPs don't use it. Later on ISPs were forced to block piratebay.org and there have been discussions about blocking online poker sites etc, because Veikkaus enjoys monopoly in gambling and betting business in Finland.