Twitter has confirmed that it will begin to censor tweets, if required by law, on a country by country basis. Until now the micro-blogging service has remained a free and open platform for millions of people worldwide, empowering its users to say and share whatever they like.

"The open exchange of information can have a positive global impact [...] almost every country in the world agrees that freedom of expression is a human right. Many countries also agree that freedom of expression carries with it responsibilities and has limits," the company said in a statement on its blog.

Like all worldwide, borderless businesses though, Twitter is required to obey the laws of the countries it is in, so in order to comply they will begin censoring content published that falls foul of laws in individual countries, rather than on a global level.

For example, in countries like France and Germany, where pro-Nazi comments and celebration are against the law, Twitter will censor tweets containing pro-Nazi comments for micro-bloggers in those two countries, whilst still allowing those that do not ban it to view the tweets.

"One of our core values as a company is to defend and respect each user's voice," Twitter continued. "We try to keep content up wherever and whenever we can, and we will be transparent with users when we can't. The Tweets must continue to flow."

The company said it would do its best to contact any users affected by the new censorship policy, and will clearly mark any tweets that have been censored. They have also extended their transparency through with a Twitter section on the site to make it easier for people to find legal notices and takedowns - currently it is mainly full of DMCA takedown requests, presumably we will begin to see tweets that are censored added to the site accompanied by the reasons they were blocked.

As one of the leaders of a free and open web, Twitter is likely to see considerable condemnation for taking this stance. It does however have little choice if it wants to avoid heavy lawsuits and government pressure the world over. Ultimately they hope to continue to allow the freedom that has enabled creativity to flow without breaking individual country's laws.