I think an always-installed bike rack is going to be the "safest" solution.

Here in Tennessee I'm also thinking about making a "frame" which extends out about 12 inches from the rear of the bumper, blocking aerial observation (but still in compliance with Tennessee law, "visible from rear at 100ft").

Our photo tickets aren't legally enforceable (across the entire state, except for automated school/bus citations), but the Flock cameras have really started being deployed over the past year.

Most of our new Flock cameras have additional security cameras prominently recording, nearby (like you'd see in a bigbox parking lot for security). I hope we can legislate these out of existance, pronto.