Censoring
IIRC, Google was told to censor the search results for certain queries to comply with Chinese law. However, whereas most ISPs and search engines apparently just return a HTTP error, Google apparently showed a page saying something to the effect of "Sorry, but I can't allow you to do that" - so people knew they'd been filtered, rather than the page being down.
I wonder what people's reaction would have been if, instead of filtering the content, Google had put up an intermediate page saying something to the effect of "We have been requested to filter this content. You may click on the link below to access it, but you do so at your own risk." In that case, Google would still be informing its users about 'naughty' content, but simultaneously still allowing access to it...