My boss can be a prat sometimes

This week's Private Eye (Eye 1379) contains a worrying article on page 9 (Tidings of Joy) which reveals that Daily Express employees have been commanded not to make disparaging comments about owner Richard Desmond or any of his friends in their Tweets or on Facebook.
This is worrying for several reasons. First, an employee should not be expected to cede all aspects of their right to freedom of expression when they sign their contract of employment. Second, an adverse comment about an unidentified co-worker, superior or manager made in exasperation or as a throwaway remark should not constitute a breach of the implied term of mutual trust and confidence that forms part of the contract of employment when to do so serves to allow the employer to intrude into an employee's personal and private life. In any event, to claim a right to control how an employee uses social media represents a gross abuse of bargaining power that distorts the employment relationship.
In my case, I can say that my boss can sometimes be a right pillock; but then again, I'm self-employed.