So the issue is not tying it to your online identity, but rather them keeping a resource which becomes more valuable as the time goes on. So why is that an issue... most obviously because of genetic predisposition. There is always a temptation to sell diseases you are predisposed to insurers (and maybe employers... ugh). After that you can imagine someone figuring that genetics affects any number of things (sugar / weight / addiction) and sell that to advertisers...
The film Gattaca covers how this could lead to a sort of night are society pretty well, I highly recommend it.
It also makes it much much harder to use the data for clinical research.
Human brains when generating 'random' numbers: https://xkcd.com/221/
> Once a month company publishes one giant zip with all the monthly result where you find your file by that random number you wrote.
Given how much of our appearance is due to genetics, that's basically all the harm with none of the convenience.
Fortunately, contemporary humans have access to computers, which can generate random numbers for them free of charge.
>Given how much of our appearance is due to genetics, that's basically all the harm
I can't fathom your concept of "harm"; and neither, I think, would any prospective customer of this service.
I'm fairly relaxed about my medical history, but it's really obvious to me that I'm weird in being relaxed.
Despite my relaxed attitude, it's still fairly obvious that this lists every genetic condition*, which in turn obviously going to be relevant to any health insurance provider that isn't banned from using it.
Monetary damages are one of the easiest ones to quantify, from what I hear.
* even those that have not yet had the relevant genes discovered, because statistical methods need a larger population
At this point we practically have a single search engine that’ll take you genetic sequence aa input and return your face, you entire family tree, your current job and address and what you do in your free time.