Ok but UK is not an oppresive regime, so that we talk about "dissidents" in UK. As anywhere, the freedom of speech is regulated. But even if you spout racist or other nonsense, you are not a dissident, you are just breaking the law, to which I agree, hate speech, racism should not be openly promoted.
The definition of hate speech used to be centered around terrorism and was initially sold to the UK public as stopping "Islamic hate preachers and stopping terrorism". This has now expanded far past that and people are being investigated and arrested for simply opposing immigration (which is often conflated with racism disingenuously), or criticising the actions of Israel, teenagers posting rap lyrics on facebook, and numerous others that I have forgotten about.
If you are not bothered by the expansion of these powers because some people have said things you disapprove of there is nothing I can say to convince you.
