When is it okay to restrict free speech?

In this week's UK Column banter session between me, Mike Robinson, and Charles Malet, we chat about what is meant by the term 'free speech' and when, if at all, it is acceptable to restrict people from speaking freely.As it happens, there are indeed times when it's okay to restrict speech — in a cinema, for example. Do you want to pay money to watch a movie and, instead, listen to the people next to you chatting about what they had for lunch? I pointed out that I won't allow people to come into my home and swear at my family.Sadly, it seems that some people don't do well with absolute freedom of speech and prefer to be chaotic trolls who ruin it for those around them.