RE: Illinois Deer Pins
If you define poaching as breaking ANY law, then I say yes, I'm sure that there are deer being shot, tagged, taken home, and processed without reporting it. Some guys would see it that as long as the (correct)tag is used only once, no foul.
If you are talking about shooting deer at night from roads, and just taking them home, I say that there is no noticeable increase. Check stations never did anything to prevent that anyway, the risk is the same.