I am sure we could have some fun!!!
I've looked into this. It's legal as long as someone doesn't have legitimate complaint about it, i.e. noise complaint near homes, the owner of the property agrees to it, and it's unable to be accessed readily by the public, i.e. fenced and not on public road ways.
I've actually asked the fair grounds about using their parking lot for an autox event when I used to be into that. They said no problem, but they wanted an arm and a leg to rent and it didn't justify the cost.
Additionally, we needed to have waivers and insurance. It got to be very expensive. However, if someone had a lot and they agreed to let a small group of people use it then there is no problem.
Legally, however, the owner of the property is responsible if anyone gets hurt or any property damage and the individuals can sue the property owner if something happens. Thus, it's a slippery slope getting something together like this and it probably won't happen unless its a small close-knit group of guys who trust each other enough not to sue their friends.
*sigh*
As a small example, there is this Nissan/Infiniti meet in Fremont in May every year and, generally speaking, it's a medium-caliber event, sponsers, dyno, track-cars trailered in, etc. The year before I went, from what I hear, a kid was trying to drift on the road leading to the event and he smacked into a tree. (another 240 bit the dust) So, obviously, a lot of unwanted police attention came down on the event and it almost didn't happen the year I went. A lot of people were upset because all the people that come to this event are pretty chill guys with clean rides just into doing what normal people do at a car show/gathering. So, moral of the story, it just takes one 240 to ruin the party...j/k, but you get my point.
Sorry for the long-winded response, but i was finally able to contribute something on here.