In fact, the latter ones are so ubiquitous, I think you would be hard-pressed to find a person in a major US city in their 20s who was single for a period of time in the past 5 years and haven't used one of those apps.
From previous experience consuming public record data sources programmatically, a proof of concept would take no more than a full day of work. I am not suggesting one do this, only that pandora's box is already open.
Or said in one word: blackmail.
There's no sugar coating it. You'd be collecting data points and analyzing them to pursue your own justice without due process. That's quite a dangerous thing to claim to want to do in the name of "insider risk management".
I don't support blackmail in any form, full stop. I do want to know if you're going to embezzle millions of dollars before you do, as do shareholders or customers (if you're managing assets) of the organization.