It's pretty trivial to find insider trading looking activity as a human, so I doubt it would be particularly difficult to write up an algorithm to do it. Of course you wouldn't come close to catching everything but you'd catch blatant stuff.
The problem is as a private citizen/company (1) you have no idea who placed the trades and (2) even if you did, you can't enforce the law.
And, as seems to be the case with U.S., even the justice department themselves have little interest in enforcing the law, making insider trading the sort of thing that on paper is illegal, but since everybody does it, it's okay.