Twitter has introduced a system that lets it censor specific tweets or block whole user accounts in some countries, while leaving them visible in others.
On Thursday, the company said it needs to be able to selectively withhold posts because it must deal with a vast array of freedom-of-expression laws around the world, as a result of its expansion into new countries. It will only do so in response to a "valid and properly scoped request from an authorised entity", it stressed.
In a blog post, Twitter noted some countries have such poor freedom-of-expression rights that the service "will not be able to exist there". However, others have more-acceptable bans on certain types of material, it said: for example, France and Germany both have prohibitions on neo-Nazi content.
"Until now, the only way we could take account of those countries' limits was to remove content globally. Starting today, we give ourselves the ability to reactively withhold content from users in a specific country — while keeping it available in the rest of the world," Twitter said, adding it will work out user location via the IP address.
"We have also built in a way to communicate transparently to
users when content is withheld and why," the company said.
In the UK, Twitter found itself at the centre of a privacy row last year, when users defied a High Court superinjunction protecting the identity of a well-known footballer involved in a legal case.
The footballer's lawyers were thought to have sued Twitter in its home country of the US, although they subsequently denied doing so. The US has stronger freedom-of-expression laws than the UK does, making it unlikely that Twitter would have agreed to censor its global network at the request of a High Court judge.
Internet law expert Lilian Edwards, professor of e-governance at Strathclyde University, believes Twitter's move is more likely to enhance freedom of speech than stifle it.
"I think on the whole it's a step forward," Edwards told ZDNet UK. "It's rather like the start of the internet, when Compuserve had to close down whole news groups if they breached Bavarian law, even if they were legal everywhere else. Granularity is generally good for global free speech in stopping the race to the lowest-common-denominator bottom."
Edwards pointed out that Twitter has no choice but to comply with legal injunctions. This means it is "best for all of us if they can be as transparent as possible about what they are being asked to do and what they actually censor in response", she said.
Taking down tweetsAccording to a new Twitter policy note, filtered posts will be replaced in users' timelines with a greyed-out message saying: 'This Tweet from @Username has been withheld in: Country'. There will also be a link to further information.
Twitter has not yet used its selective censorship capability, it said. When it does need to do so, it will first try to contact the person whose tweet or account is targeted. In addition, it will list instances of filtering on a special Chilling Effects page.
Chilling Effects is an online archive used by Google and others to record takedown requests arising from US Digital Millennium Copyright Act (DMCA) notices. The archive's Twitter section includes dozens of DMCA notices demanding the removal of tweets that link to copyright-infringing material. From now on, the page will also list the censorship requests from other sources.
Twitter will attempt to notify affected users of the takedown request via the email address it has on file for that account. The email will identify the content affected, who is making the takedown request, while the person's timeline or account will have a "visual indicator" of what has happened, the company said.
"It is then up to the user to decide whether they would prefer to leave the content online, challenge the underlying request, or, if they choose, to delete a Tweet or deactivate their account," Twitter said.
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