At least in the US you own your image. If it is used with your consent you should be compensated by whatever way was agreed upon. If it was used without your consent, well, just ask how many zeros come to the left of the decimal point. If it's used by law enforcement, well....
Surely 0.50 is the same as 00000000000.50
Unless you mean how many zeros come up between the first significant figure and the decimal point.