[felix_nagaand]

Pebbles in one or both shoes, plus a thick insole, and some sort of tourniquet on a leg just loose to allow blood to flow will be sufficient to trick these for sometime so long as one can carefully conceal any other uniquely identifying factors.

[pixl97]

I can only imagine getting caught trying to defeat these systems will have horrifying ramifications.

[onetimemanytime]

The system needs to be right one time only. You cannot afford to make a mistake and odds are stacked against you. You cannot do that unless you are wanted for xx years of jail, otherwise it's too big of a burden...day after day.

Plus, they'll know by your smartphone (pay, map++ apps) where you are. Merge the data and there you go.