Most parks require a permit to fly which is given with proof of insurance, the permit is only as good as the term of your insurance. If your insurance is paid monthly, then you'll have to get a new permit every month. The good thing about the AMA card and why the parks dept likes it, is because it's always an annual subscription that starts and ends on the first of each year. Your premium is always paid. Parks departments know all the games and tricks, they deal with the EXACT same situations with Soccer and Baseball leagues long before a RC field hit their park, it's no different. Soccer and Baseball leagues also have their National sponsor/insurer programs as well. Also who said a public park was public? The public park is only "public" to it's residents if that's what they want to do. Municipalities could put fences around their parks and only allow their local taxpayers to use the land and in some parks they do just that. A permit just to use the park. They can also institute as many rules as they wish as well as long as they are not discriminating within their community. Now federal parks, that's a different story.

Anyhow the guy in the thread never mentioned a park anyway ... why did it go this direction?