Here's one thing we know about Twitter: people can say whatever they want on it.
Sometimes that leads to brilliant 140-character expressions, and sometimes it allows people to say stupid, hurtful things. But to date, the site has never stepped in to prevent anyone from Tweeting as they see fit.
Today, Twitter blocked an account for the first time in its history.
The account in question belongs to a German neo-Nazi group. Twitter has blocked @hannoverticker within Germany at the request of authorities there.
Although Tweets from the account are no longer visible inside Germany, the rest of the world can still see them.
The account belongs to the far-right group "Besseres Hannover" ("Better Hannover"). The group was banned last month by Lower Saxony's government for promoting Nazi ideals and undermining Germany's democracy.
The government sent Twitter a letter asking the company to "close this account immediately and not to open any substitute accounts for the organization."
This shot is from a press conference held September 25, where authorities displayed a Nazi flag found at the Besseres Hannover headquarters.
Twitter announced back in January that they were creating a feature that would allow them to block accounts locally. Some people were outraged that the service, which is used by dissidents and activists, would limit freedom of speech in any way.
Kirsty Hughes, chief executive of the UK-based free speech advocacy group Index on Censorship, weighed in today. She said Twitter's decision was mainly about German laws prohibiting extreme right speech than about company policy.
"We would argue it is perfectly fair to ban speech that is direct incitement to violence, but not to ban speech that is just extreme and doesn't incite violence," she said.
"However many years after the second world war, the question is, is it still appropriate, and whether it was ever appropriate (in Germany) - that's the source of this decision today, rather than Twitter being where one should point the finger."