I've wondered how they might adapt to things like Leonization. "Mr. Reynolds, it says here you're 56?" Yep. "But you look 26." Yep.

All the more reason to be able to prove your age at all times

Never heard of Andy Milonakis? Actor who's 39 and looks 14 due to human growth hormone deficiency. Eric Millegan also doesn't look over 17 (he's 39).

There's other examples too, but really, two is sufficient.

No, it's really not sufficient, because those two probably get a lot of issues in their daily life. So just proving there are examples says exactly nothing about what happens when their IDs are checked ... by let's say a power-mad hick cop with limited imagination during a routine traffic control.

I suppose a Leonization marker in your SIN would be potentially helpful in other ways. The idea that Leonization = Money to do it = Money to make things difficult for you, wageslave cop.

Or they might think you're a good extortion target.

Also, so where are the SINs 'stored'? Not so much for purposes of their records (thats national+megacorp server level stuff), but when you buy a fake SIN, are you buying a number that you use the net to 'link up' with? Is it like someone handing you a 'normal' fake ID, with a physical passport that then also links up to records? Since your SIN can link up with your commlink and stuff, is it basically just a number you enter and go, "This is me.", like anyone can use anyone elses Social Security Number if they know what the number is, but in this case, the info won't link up beyond the most limited check.

So when I buy a new SIN (Fake) do I get handed a little slip of paper that tells me what SIN number now sorta matches the biometrics/etc I wanted, do you need to 'verify' who you are with that fake sin to link/start using it? Considering hackability, I'd say it'd be a bad idea to keep your multiple fake SINs on one Commlink, so where would be a good place to store them until you need them (assuming you don't have perfect memory). A shadowsite safe deposit box in the net somewhere?

It occurs to me that having a SIN that doesn't quite match you could also be a benefit. Make a fake "father" and have that SIN used to hold property that you have access to. Potentially though that could mean losing 2 SIN if your 'son' SIN gets burned or vice versa. Or if you don't want a direct connect, make the 1 SIN your 'landlord' and then your other one the tenant which could get burned without always burning the primary landlord one.