The UK has extensive gun control laws. It hasn't stopped people from doing terrible things, however.

Part of the issue is that terrible people do terrible things and you're never going to stop them. Yet sometimes, the laws meant to stop those terrible things are in place, but something happens to make them completely ineffective. The issue is that people are involved in the process, and people are fallible, as we all know only too well.

A recent incident brings that into sharp focus, as does the father of a Dunblane victim calling for a "hotline" to report people for disturbing behavior.

The father of schoolgirl killed in the Dunblane massacre has called for police to reintroduce a “hotline” to report erratic behaviour by gun owners after the sentencing of a man who carried out a murderous rampage on the Isle of Skye.

Police officers should also be able to consult health records before granting or renewing licences for owners who display concerning traits, according to the Gun Control Network (GCN), set up after the killing of 16 children and their teacher at in 1996.

Finlay MacDonald, 41, from Tarskavaig was jailed for life last week after repeatedly stabbing his wife Rowena and then using one of his six legally owned guns to shoot dead his brother-in-law John MacKinnon, and seriously wound osteopath John Mackenzie and his wife, Fay.

But although he was showing disturbing behavioural traits prior to his violent rampage and he was known to be struggling to get “referees” to vouch for him, he was allowed by police officers to keep his gun licence.

The GCN, set up by Dunblane parents, academics and lawyers after the mass shooting to campaign for tighter gun laws, said a hotline would allow members of the public to report their concerns.

Such a hotline was launched in November 2015 but was withdrawn in January 2016, apparently at the behest of senior cabinet members in David Cameron’s Conservative government, who felt that the phone line would “criminalise” law-abiding gun owners. Since then there has been no progress with its reinstatement.

Now, what we're seeing is them pushing this while pretending it would have stopped the shooting.

But there's an interesting bit that I'd like to talk about here that will get into why no one should be moved by these arguments.

In World War II, engineers looked at where planes were being shot up. The idea was to armor those places to make the planes more survivable. They found that most of the bullets were focused on parts like the inner and outer parts of the wings, the fuselage near the wings, and the tail, and that was it. So, it was clear that they needed to armor those sections of the plan.

However, someone pointed out that the problem points weren't there. These were the planes that returned. 

The places where few bullet holes were found were discovered to be the most vulnerable parts of the plane, but those didn't survive, so they were likely to be missed. This is called "survivorship bias" and it can be an issue because what survives can skew perceptions.

Now, let's look at this hotline thing. It won't be the same thing--not quite, anyway--but there are some strong similarities to the survivorship bias talked about above.

In this case, we have them presenting a case where it might look like this hotline would have done some good, particularly under UK law. It's not looking at all the people who were wrecked the last time such nor the incidents where it wouldn't have done a bit of good.

They're focused on this one instance where they're convinced it would have changed everything.

They consciously ignore the "false positives" of people who are reported for no reason or who are reported as a means of punishing them for something. They ignore the numerous cases where it wouldn't have mattered, then present the one case where it does and argue that yes, this whole thing could have been averted if we'd done just one thing.

I'm sorry, but that's not a convincing argument.