I totally agree with this. One thing that should be noted is that in this case the government was acting in the corrupt interest of the incumbent taxi industry

I totally agree with this. One thing that should be noted is that in this case the government was acting in the corrupt interest of the incumbent taxi industry. Once the system has been corrupted, tactics like Grayball become the only way for any company to disrupt the industry. My guess is that Grayball was used most in jurisdictions with the most corruption and regulatory capture inflicted by the taxi/livery industry.