Ok, this is in the family of the other discussions of SR4 being too much like surviving IN the spotlight, vs. SR3's avoiding the spotligt.
Basically it sounds like it is accepted that turning of your commlink in some areas of high security is a bad idea. Sec folk like knowing, at-a-glance, who you are.
However, most runners buying new stuff or even stealing stuff, go home and put it under ye olde Tag Eraser to get rid of any and all chips that might leave a trail at some later date.
But in doing so, are they actually raising a flag for a clever sec-boy to discover? - If it is a felony to own a tag eraser, EVERYBODY else is wearing a sign on each and every single piece of clothing they wear. If nothing else, broadcasting the brand name and where to get your own.
Ye typical runner will not be doing this, even if his commlink is compliantly broadcasting his fake-SIN, his cool new sneaks will likely be very silent as he plans to slide into an alley and break into a backroom where he will turn off his commlink and go invisible from a scanner point of view.
So, if you enter a high security area, will it be reasonable if the guards ask why you have turned off the tags in your shoes? - Because, thats kinda impossible for a law-abiding citizen to do...
THE SHOES!!!!