The reason I wanted to voice my opinion was to present an alternative point of view to the people who asked the question. The way you presented a runners ability to obtain highly sensitive data on his or her team mates with nothing but a DNA sample didn't mesh with my view of the setting or the technology in it, so I offered my own opinion as an alternate interpretation of the source material.
I feel there is room for both, not necessarily in the same fictional world at the same time but certainly for people to make up their own minds, and I have no issue saying so.
As you aren't the original poster, I feel no need to respond more than this to this part of your statement/query.
*shrugs* I play with the world as described, for the most part, with pretty much only simple logical extrapolations. You CAN send a DNA query to the SIN registry; you could even send a DNA query to corporate databases, and here's the kicker: if that corporation is looking for your DNA target, and they have the information, they're going to let you get it - because they're going to trace you by that query, show up on your doorstep, and ask you to point out DNA Target Guy. If you're connected, you might be able to do it on the down-low, but again, Medicineman (and others), you seem to be playing strictly by only what gear has been given, and not extrapolating it at all.
I would say that the eventuality you describe here is vastly diferrent from your previous description of how a runner could obtain sensitive information about another team mate or Johnson. My issue with either is that access to such information should not, in my opinion, be so freely available because of the potential catastrophic consequences this could have for people like corporate born runners and Mr. Johnson, whoswhvery lives rest on keeping information about their past hidden.
But it isn't different in the least. My original statement may have left out details, but there's no difference between the two at all. See, this is where I run into the issue of 'I've been playing this game for so long, what I'm telling you sounds like opinion but is 15-year-old fluff.' Knowing and internalizing the game's background and in-character postings in the published game world in regards to SINs - or anything else! - makes me sound like when I say stuff like this, it sounds like it's my opinion, bullshit I make up on the spot, when it really ain't. I may not remember precisely where it comes from, but it's in there, and if I absolutely had to track it down - for example, if I were writing officially about this - I would absolutely do so in order to confirm my sources and make sure it fit with the prior canon. I don't generally do that, though, so because I don't quote book and page, it sounds like - as you say - opinion.
Additional details for people such as a Corporate Johnson would be similar to 'they let this information out on a strictly need-to-know basis, for the security of a valuable corporate asset'. In addition, you seem to be presuming that nobody can send a query to a corporate SIN database; if that were true, then corporate citizens would get arrested strolling around outside their arcologies, because they aren't broadcasting a legal SIN. In truth, SIN queries go to where the SIN says it originates from. The first characters of a SIN give the SIN reader the origin - in essence, the database the reader needs to query to discover whether or not the SIN is valid. Countries pretty much post theirs to their own national databases and to the global DB; criminal SINs wind up there too, because everyone wants to know that the Bad Guy is a Bad Guy.
A reader, however, is going to look at system identification number 'SRKP823-1235-19273A-45F' and go poke at the Saeder-Krupp database. While details of a corporate SIN aren't going to be immediately available, the keys in that corporation's database and the SIN reader's identity and rating (which I would imagine would include a permissions list which improves as the reader's rating improves) are going to indicate how much information to share with the SIN reader. A SIN reader that transmits an identity of 'SK-Prime' is going to get every iota of information for the aforementioned SIN; a reader that transmits 'Renraku Security' might get 'yeah, that SIN exists, but we ain't gonna tell you even what gender or metatype the entity in question is' - or it may deny that it exists, if that SIN is (for example) for a deep-black corporate Johnson.
The bureaucracy that you want interfering certainly does interfere - but because every gear in that bureaucracy has its own agenda, it may turn fast or slow, depending on who you are, why you're asking, and how those two fit into that agenda.