Half security is no security

Let's start with an example:

For various goods there are those special anti-theft-tags used in shops to prevent people from shoplifting. Most frequently they are used for CDs and clothing.

Now, often these tags themselves cost quite a bit of money. After all, they usually contain some kind of sender as well as an intricate system that allows easy removal with the correct tools, but at the same time has to make removal without those tools as hard as possible.

Not to mention that they frequently get lost, damaged, or [ironically] stolen.

In short, anti-theft-tags are an important cost factor in any anti-theft system.

A fact to which some managers have rather peculiar solutions. I wish I could explain their reasoning, but I'm at a loss for even remotely comprehensible explanations. I'll therefore stick with the observable facts: Once in a while, I walk into a shop and notice that roughly every second or every third item in a shelf is tagged with an anti-theft-tag, while the rest is not. And I don't mean that pricey items are tagged and cheap ones aren't -- no, of exactly identical items, only every second is tagged.

What are they thinking?

That they could at least get half the possible security out of it?

That there would be a 50% chance that a thief would pick one of the tagged items?

That this [alleged] risk would prevent thieves from even trying?

Dear shop managers, I shall enlighten you, free of charge, with one of the most basic principles of ... well, common sense: If there are two identical items, and one has a huge anti-theft-tag on it and the other hasn't -- guess which one a thief will take? (Take three guesses if you have to.)

The moral of the story: There is no such thing as half security. It's like locking the left car door and leaving the right one wide open. Or hiding top secret documents in a safe and leaving a copy on the copy machine. Or using half a condom. Or guarding a prison exit door only in the afternoon. Or ... Well, you get the idea.

If there are two ways, there's simply no point in securing only one of them.

-- Birgit

P.S.: More examples of this are sure to follow. I wasn't surprised that it happens at all, but I'm surprised time and again about how frequently it happens.