You really don't want to do that.

We use one of those services, too, and you have to use a very light touch. Just using them at all makes people paranoid. If there are people you find who pose a risk, yes, you should do something about that, but terrorizing your workforce is a terrible idea for multiple reasons.

> putting their own employment at risk

Even looking at it amorally, that only really works in declining industries where people don't have a choice. Do that to engineers in a hot economy, and I suspect you'll be employing only the otherwise-unemployable soon.