Terror alert raised to severe

I read that the UK’s terror alert level has been raised to “severe”.

We are urged to be vigilant. But there’s no intelligence indicating an imminent attack. And nothing in particular that we’re supposed to do, or not do, depending on the terror alert level. I rather suspect that, if it ever goes back down to “substantial”, we will still be asked to be vigilant.

It’s almost like it’s… pointless?

Edited to add:

@glynwintle just sent me this:

Nails and heads spring to mind!