I would say that there is no specific social media site that is blocked in Malaysia. We, Malaysians embrace social media tools. Our prime minister has a Twitter account and uses both English and Malay to communicate with his followers. Here’s a screenshot from his Twitter account related to the MH17 incident:
The nation’s number one singer is also active on her Instagram with more than 6.6M followers:
There’re also Malaysian youths that are actively sharing their thoughts on Youtube and use English as their main language to communicate:
Other than that, there is also an annual event, the Malaysia Social Media Week hosted by a non-profit organization called the Social Media Chambers. The highlight of the week is the awards for Malaysian bloggers. Some of the categories of the awards are Best Auto Blog, Best Foodie Blog, Best Business Blog, and Best Lifestyle Blog.
The Berita Harian Annual Awards is another event that give awards such as the Most Influential Artist on Social Media and the Most Popular Artist on YouTube. The event also hosts a “Social Media Party” for people who couldn’t go to the event but can share Tweets, Facebook and Instagram posts with #ABPH and #ABPHSELFIE tags.
Despite the Prime Minister promises that Malaysia will never censor the Internet, there are times when certain YouTube videos or blog posts that were politically sensitive, banned by the Malaysian government. In addition, the government also blocked WikiLeaks, The Pirate Bay, and several file-hosting website. I found this information here, on Wikipedia.