Muhyiddin said Barisan Nasional would not tolerate lies spread via social media anymore.
Dear BN, when you say that, I can infer that what you really want is people to stop public discussions about the government and it's actions.
While not everything discussed online are lies, and one could see BN's message as merely a warning like something your mother told you never to do (i.e. tell lies), one should wonder if political discussions do indeed entail lies? Generally, when you talk about the Teoh Beng Hock cover-up or any other scandals and news over coffee with your friends, your discussion covers, but isn't limited to, what was reported in the news, what the alternative media reported, and speculation as to what really happened (i.e. your own ideas about the situation and/or ideas you heard from someone else). Isn't this, then, a critical discussion about politics?
That said, I want to shift your attention to the role social media plays, how it empowers the public.
Before social media, the public discussed politics in their own little offline communities, wrote in to newspapers, and whatnot. Then in the early 2000s, the Internet brought social media to the table. The public could now discuss politics in another space and they had the tools to help them do that too. Tools like Twitter, Facebook, and blogs amplify and publicize the offline chatter that exists amongst people. It is this unprecedented freedom and power in speech bestowed by the public, that reaches every corner of the Internet, that is threatening BN.
Dressing political discussions in social media up as lies makes the government, in my opinion, look cowardly and oh so cunning. With their streak (i.e. strict publication laws and regulations, no freedom of speech and liberal use of the ISA, etc.), it's not hard to think so.