Not long after Turkey's prime minister imposed a ban on Twitter, Internet users in Turkey went on - what else? - Twitter to find ways to circumvent the blockade. Twitter Inc. and Turkish news media also shared some tips, as did Turkish residents through low-tech means such as graffiti and street posters.
The response to the ban shows why it's difficult for governments to control the Internet. China and other countries notorious for censoring content have routinely faced efforts by citizens determined to bypass their controls. And in Turkey, people were still tweeting on Friday.
Here's a look at the ban and the ways Turkish Internet users are circumventing it:
Q. Why is Turkey banning Twitter?
A. The ban came as Prime Minister Recep Tayyip Erdogan threatened to "rip out the roots" of the social network. His remarks came after links proliferated on Twitter to recordings that appear to incriminate Erdogan and other officials in corruption. Uproar over the recordings has damaged the government's reputation ahead of local elections this month.
Many people who tried to visit Twitter on Friday got a blocking notice from Turkey's telecommunications authority that referred to four court orders.
Q. How is Twitter being blocked?
A. Internet access providers in the country are redirecting Twitter traffic to a website that contains the blocking notice. It appears that Turkish Internet providers are doing so by changing the numeric Internet Protocol address associated with Twitter.com.
Think of the domain name system as an Internet phone book. When you type in Twitter.com, your computer looks up the numeric IP address for Twitter's website and takes you there. It's similar to the way you can make calls on your smartphone by looking up your friends' names rather than memorizing all the phone numbers.
Turkish service providers can steer you away from Twitter's website by putting an incorrect IP address for Twitter.com in their domain name servers.
Q. How are people still tweeting in Turkey?
A. Users can change the "phone book" their computer uses. The domain name system has multiple copies of these phone books, all of which are supposed to be identical. The Internet access provider usually picks the one used, but users can change settings on their machines to a different one. That way, Twitter.com would pull up the real IP address for Twitter's website.
People also can use masking services called proxies. A person's PC or mobile device connects to the proxy, which uses its own domain name