The prime minister did go on a dodgy trade trip to South Africa in 1989, but tweets alleging that he wanted Mandela executed while a student are mistaken.
An emerging field of research is making it easier to track perpetrators by looking at the way they use language when they chat.
Daisy Coleman is the latest in a series of girls to report that they were sexually assaulted and cyberbullied on social media. But we can't blame Twitter and Facebook for the existence of rape culture - and with #justice4daisy, they might have helped end it.
We’re swamped by a tide of reaction and instant opinion churned out by the second on Twitter, writes Jason Cowley. But as Franzen, Obama and Miliband show, instant gratification won’t secure our grasp of events.
Police officers told Caroline Criado-Perez that they would collate the necessary information on threatening tweets sent to her. But earlier today, she was told that only individual tweets she had reported were being investigated. She now wonders if it is was worth reporting any of the abuse at all.
The latest update to the social network is simply a helpful little line to make it easier to follow a conversational thread. In reality, it will mean that the clubby little chats of the great and good will be even more difficult to avoid.
Instead of throwing around words like "mansplaining", we should try to understand each other's experiences - which are as unique as our individual perception of colours.
...just like it did to Facebook.
Say hello to a world where you can just do stuff, without talking about the stuff you're doing!