Destroying those mining rigs isn't the solution, it might send shivers to would be miners but this isn't a lasting solution.
For your information People have tasted the profits that come from mining, don't expect their new found lifestyle to be halted just like this, they will become much smarter about it and continue mining their cryptocurrencies.
What for? Have they found no other use for miners?
They could have auctioned them and proceeds sent to electricity providers,what a loss for everyone.