Airport Security

Saw this sign in Heathrow Airport:

What is this suppose to mean?

1. The rest of the airport is NOT secure
2. Because of me, they now have to secure it
3. Im a terrorist, and I now need to be aware that I shouldnt be
   
4. Its a reminder to airport staff to be more vigilant

Argh. Whatever that sign is suppose to mean, it does NOT make me, an innocent passenger feel any better.

WTF.

yk.