Hi
In the north west we have had lots of problems with them using death rigs suspended from poles stuck into bank side then taking the carp for others.
When we see anyone on the bank, we challenge immediately demanding to see licences.
This often does the trick but we are still looding valuable stocks when we can not balif the waters 24/7
If they are caught, all that happens is a slapon the wrist because they do not generally have tackle to confiscate.
Good luck with the balifing of your waters mate