Carol Vorderman and Gary Lineker have been very vocal on social media, but only one of them have lost their job.The BBC’s announcement of an independent review of its social mediaguidelines was aimed at defusing the crisis over Gary Lineker’s tweets over government ministers’ language about its asylum policies and bring the presenter back into the fold, at least in the short term.However, the practicalities of creating a set of rules to rein in star behaviour, while avoiding accusations of stifling free speech, are far from straightforward. What is to be done: Mark and Pete have the answers.