The recent incident at Fir Vale School illustrated only too well the power of social media for good and ill.

On the one hand, pupils at the school were able to get in touch with their parents instantly on their mobile phones. Within minutes those parents began to appear at the school gates to see for themselves what was happening and that their children were safe.

I am sure it must give parents some comfort to know that when they say goodbye to their children in the morning they are not cut off from them until they come home again later in the day.

This is all very different from the time when my own children were in school and mobile phones were unknown. You had no idea where they were, who they were with or what they might be doing and no means of asking them. If they were unduly late, you worried.

So the mobile phone and social media can be a blessing. It can also be a curse.

There was another side to what happened at Fir Vale. Instant communication also allows for rumours and misinformation to be spread very quickly. And unfortunately there was a great deal of that.

A small local incident of the sort that any school might have to deal with on a day to day basis was suddenly being escalated. Rumours of weapons being seen quickly spread, even though this was not true.

The emergency services, including the police, responded in numbers.

It’s part of my job to ask the chief constable whether that response was proportionate, which I did at my monthly Public Accountability Board – a meeting that is held in public and to which anyone can come.

The answer was that until the police arrived on the scene they had no way of sifting facts on the ground from the rumours swirling round social media.

The prime function of the police is to maintain good order and to keep us safe, so they will naturally keep deploying available officers until a situation can be assessed, brought under control and everyone made safe – which is what happened.

But it should serve as a lesson for all of us to think very carefully about what we say on social media.

Loose talk and misinformation is quickly amplified.

When that happens it’s like shouting ‘Fire’ in a crowded cinema.