I think you are getting a bit confused here, you seem to think that i feel it's alright for a business to fire someone for doing silly pranks or something. I'm not. But i don't oppose a business for firing someone is showing extreme views, eg being a racist, throwing out hate speech, threatening people. If someone shows that kind of behaviour on a consistent basis, i have no problem with a company firing them, maybe they'll learn to reel it in then.
How do you discern a prank / fake / wind-up from truth in a seemingly anonymous post on a forum / bbc comment site / etc?
I'm not getting at you with that, I would be more happy with a genuine explanation of how you think that could realistically function.
This is where the censorship goes far too far the wrong way and becomes thought police.
I can understand the desire to weed out the truly hateful... on the other hand, I also think people are basically good at heart, like you do... so if someone is so hateful, there is likely a reason for it and something like education or simply the loving acceptance of another human would be more likely to have a positive effect on them than ostracizing them which will only amplify the hate.
I am not saying that I think you think it's ok for a business to fire someone based on a silly or mis-placed comment. What I am saying is that with such legislation and policy such as the one from the BBC T&Cs that was posted in this thread... it will be impossible in many cases to discern the difference and innocent people are going to be punished for it more than the guilty ones.
Let's take this a step further and apply the basically good heart to these policies. Perhaps the ones who have drawn them up have a similar viewpoint... but the potential for mistake and abuse is so high, it's just not worth it and as such, it is not a viable policy. Their inability to think like that or to at least consult someone who can think like that, makes them unfit leaders.
A fit leader can admit when they have reached their knowledge and experience level and draw that information from better qualified sources.