Quote:
Since when are street transactions illegal?


The presentation of the statistics here gives us

"Street/illegal source" Now, it is not street and illegal sources, it puts them together, so i am to assume that all of these are basically illegal transations that may take place on the streets.

Now, this is divided up into three categories, so "Street/illegal source" means;

Theft or burglary
Drug dealer/off street
Fence/black market

I take it that theft, burglary, drug dealers, black market are all illegal, fence appears to be an american word for a dealer in stolen property or dealing in stolen property, i take that as illegal as well.
Off the street could mean quite a few things but here i take it mean an illegal transaction of some kind, because quite frankly the context we are dealing with does not make it plausable that two people meet and make a legal transaction whilst on the street.