[jandrewrogers]

There is no reasonable way to definitively control this, though explicit theft of trade secrets between companies is prosecuted in practice and dangerous enough that ethical companies are careful about even the appearance of impropriety.

Where trade secrets really leak (in tech), in my experience, is engineer to engineer. A chat between friends over beers about some technical problem. It is nearly untraceable and it doesn’t involve anyone leaving their job.

As a fun example, database tech is buried in trade secret restrictions and has been for decades. There is a classic problem in cache replacement algorithms that has no solution in literature. Nonetheless, an astonishingly elegant solution exists — the kind that you can’t believe you never thought of it yourself after you learn it — that has been selectively passed around informally among practitioners for (at least) a decade or two. No one knows who invented it but it was likely developed at one of the old database research powerhouses like Oracle, IBM, et al that have severe trade secret regimes. A trade secret that leaks isn’t a trade secret, but there are enormous punitive consequences if anyone knows who leaked it.

This kind of trade secret leakage happens even under non-compete regimes and it is pretty common. When it happens, the probability of figuring out how it happened is very low. It has to be part of your risk model.