A thought...

If we have rules against insider trading to prevent those in the financial industries / stock exchange from making money on specialist knowledge...

Why do we allow laywers to become politicians?

After all, they know the law inside out (in theory), they have a vested interest in lawmaking, and when placed in a position of political power - they can pass laws which can effectively benefit only themselves financially (whether it be in directly via case fees or via inderect schemes such as speed cameras etc).

Why dont we have any rules in place which prevent or restrict the number of lawyers who make our laws?

They should only be allowed to interpret or advise on existing law, imho.