I'd agree with that. Certainly not something that could be or should be stopped, or worth worrying about.
But there's a fine line between vigilance and paranoia. Sometimes a vigilant public is going to report false alarms. They just will. But we have to be careful before we start discouraging people from reporting things that they see that "just don't look right". Of course it's a completely subjective standard, and different people will look at the same thing and have different instincts about it.
But its not paranoid, nor is it somehow giving victory to terror, for people to be able to decide that something looks out of place or suspicious... and to report it to those who can take a closer look. The overwhelming number of reports *will* be false alarms. That's just the game of numbers. Eventually, though, it will be the real deal. Then the person that was observant enough to react correctly will be called a hero. That's just the way of things.