The DNA you leave behind when you touch things can actually be more useful than just the cellular DNA isolated from a genome test and put into a database.

DNA analysis of your microbiota can indicate more than just what you are or who you are, but also your current health status, where you have been, and who you associate with. It would also be one way to distinguish between identical twins.

Identical twins have the same DNA.

Sure, but they have different microbiomes.

The problem is. The bad actors are stealing your data from the dna companies, not from your house...

There's a reason databases exist. Consolidated and normalized data is light years easier to obtain and less time consuming than seeking out individual pieces of disparate data.

If a bad actor wants to rob you, they can break into your house. But my door still has a lock on it.