I'm not saying you should, but cheap laser pens can do fair damage to a camera CMOS sensor.

I discovered that with my Sony Ericsson k700i with a laser pointer when trying to take a picture of the laser.

That's probably way more effective, efficient, and destructive than aggressively fouling the solar panel. Hopefully, picture quality isn't something they monitor because it would be kind of difficult. And, it would be best to unlock a Flock camera to verify that damage is possible using a specific laser pointer, distance, and time period. Then, someone might think about doing it behind concealment and/or far away enough to be below the threshold of identifiable pixel resolution.