Despite the ban in place, users in Turkey can still tweet via SMS.

Turkish Prime Minister, Tayyip Erdogan has banned social media platform Twitter throughout the country. He had earlier threatened to shut it down as he is currently caught up in a corruption scandal.
He criticized the site by calling it "Twitter mwitter!," which roughly translates to a phrase "Twitter, schmitter!". "We will wipe out all of these," he added threatening all social media networks as he blamed them for serving as platforms for a smear campaign by his political enemies.
Turkish users who were trying to open Twitter.com website were redirected to a statement from Turkey's telecommunications regulator (TIB), according to Reuters.
According to Turkish newspaper Hurriyet Daily News, Twitter was blocked 12 hours after the Erdogan made the statement. “We now have a court order. We’ll eradicate Twitter. I don’t care what the international community says. Everyone will witness the power of the Turkish Republic,” Erdogan said at a campaign rally in Bursa on March 20.
Turkey has now joined the like of Iran and Egypt who have also blocked access to Twitter and site remains banned even now.
Turkish journalist Erdem Arda Gunes told the Daily Dot that "“The ban started after midnight and got into effect gradually depending which internet providers they used, but it’s a court order (actually four different courts) which means every provider, including GSM companies, are obliged to implement this ban.”
Despite the ban in place, users in Turkey can still tweet via SMS. The San Francisco-based company Twitter offered them an alternate method to use the platform even though the company has not made any official statements regarding the issue. Turkish users can send tweets using tweets on Avea and Vodafone by texting START to 2444 on SMS. On another service provider Turkcell, users need to text START to 2555.
Users on various social media platforms throughout the world have now started comparing Turkey to Iran and North Korea; countries that are known for controlling free speech on the internet.
Two weeks ago, Erdogan had also warned that his government might ban Facebook and YouTube as well.