Flickr's introduction of content filters in Germany last week has provoked protests in blogs and web forums globally.

While in most countries the photo sharing site's "SafeSearch" function can be turned off by users interested in seeing all the photos available on Flickr, that option has been axed in Germany due to "stricter legislation and penalties in that country", parent company Yahoo! said in a statement.

Yahoo! says it isn't about censorship and that it is trying to improve the use of filters while still complying with German law.

The limitations were introduced because German law requires websites to verify that visitors are old enough to see potentially sensitive content, such as erotic photos.

Users are now calling for boycotts. One group, Against Censorship at the Flick, even created a pool of images that German users are not allowed to see.

The reactions have surprised both Flickr and Yahoo!. "We apologise that this happened in the first place, and we'd like to have more to say: there's almost nothing in the world that I'd enjoy doing less than deciding what grown-up Germans are or are not allowed to look at," one Flickr staff member said.

Flickr encountered similar criticism when some of its photos were blocked in the United Arab Emirates and China. ®