Swansea Student Liam Stacey has been sentenced to 56 days for a “racially aggravated public order offence” after tweeting a very poor taste joke about footballer Fabrice Muamba followed by several racist and inflammatory comments.

The 21-year-old claimed he had been drinking all day and was quite drunk by the time he’d sent tweets. This is most likely true. It was St Patrick’s Day and the last day of the Six Nations rugby championship, and quite a lot of people would have spent that day in the pub. But while it may be true, it’s hardly a defence.

Is Stacey a racist? A troll? A drunk and mouthy young man? Possibly a little of each. But none of these are illegal. Stacey’s conviction is for a public order offence.

One can understand why public order laws exist. The police may need to be able to take people off the streets to prevent imminent violence, and be able to punish people for causing disruptions.

But was there actually any risk that Stacey was threatening public order? I don’t think there was. A row on Twitter is not the same thing as shouting abuse in the street, where there may be immediate physical consequences. Twitter may be like a pub, in the sense that it’s a space for social interaction, but it’s definitely not the pub in that when tempers fray, no one’s going to get glassed. The worst that will happen is someone will block you.

Only one of Stacey’s tweets was violent in nature, and that did not contain any racial abuse. So has he been jailed for eight weeks solely for being offensive at a time when people on Twitter were congratulating themselves for the outpouring of goodwill to the fallen Muamba? If so, then people who care about free expression should be very, very worried.

Padraig Reidy is news editor at Index