This is Peter Hitchens's Mail on Sunday column

For years there was a site on Facebook called ‘Peter Hitchens Must Die’. I thought it was funny, and I miss it now it has gone. Hardly a week goes by on Twitter without some Left-wing oaf going online and wishing I was dead. Sometimes I write back and ask if their mothers know they are doing this, but I haven’t hired a bodyguard yet.

In short, the internet is crawling with stupid people saying moronic things they do not really mean, like the man who said he was going to blow up an airport because it was closed by snow.

Dealing with this is a simple matter of proportion. The ludicrously over-rated Home Secretary, Mrs Theresa May, obviously has no such sense. She claims to think that the terror threat to this country is now ‘greater than it has been at any time before or after 9/11’, a comically wrong belief.

Actually, the greatest terror threat this country ever faced came from the IRA, as some of us remember well. But we got rid of that threat by surrendering to them, which is perhaps why everyone now forgets it.

If this country is now a target for terror, it is largely because the terrorists know that we will eventually give in to their demands, just as we gave in to the IRA.

There ought to be a museum in which politicians’ bombastic statements after terror outrages, vowing revenge and justice, are displayed beside the eventual shabby outcomes of terrorist pressure.

Yet these same two-faced cowards are constantly trying to pretend that they are our noble protectors against a shadowy foe. They do this especially when they are trying to steal our liberties.

Now, because the drug-crazed killer Michael Adebowale made an unhinged threat on Facebook, we are asked to support the secret-police surveillance of the internet.

On the same logic, we might as well allow MI5 to open all our letters, listen to all our telephone calls and bug our bedrooms, and for this creepy snooping to be allowed in evidence in court.

I don’t see how this differs from the powers given to the East German Stasi.

Not merely is this response crass and wrong, it is based on a total, wilful misunderstanding of the murder of Lee Rigby. We are looking in entirely the wrong direction, and so not seeing the blazing, illuminated signs which show what is actually going on.

Adebowale was obviously crazy when he committed his crime. An eyewitness, Cheralee Armstrong, told police he ‘looked mad, like he’d escaped from a mental hospital’.

During the trial of Adebowale, and of his accomplice Michael Adebolajo, newspapers received a very unusual warning from the judge that they must not report ‘the demeanour of the defendants’ on the video link from prison. What was it about their behaviour that prompted this strange instruction?

It wouldn’t be odd if they had behaved weirdly. Both killers were habitual users of cannabis, a drug increasingly correlated with mental disturbance, especially in young users. It was after Adebolajo began smoking the drug in his teens that his character wholly changed. Many sad parents of ruined teenagers will know about this process.