Why would someone take a picture of the back of my car on the freeway?

[EdAragons]

I was driving on a freeway following a new GM pickup truck on a safe distance and just flowing with the traffic, driving about 70mph on the fast lane. Suddently, the driver (man) of the pickup truck in front of me switched to the right lane, let me passed, and went behind my car on my lane. He took a picture of the back of my car with license plate while driving on the freeway. I noticed he was driving alone and then he changed to the 'car pool lane' and driving next to me on the driver side and suddently took a snapshot of me with his cellphone. Isn't this illegal using a cellphone while driving and a single passenger driving on a car pool lane? I thought to myself... this is odd, what is he up to? After taking pictures, he speed up from the carpool lane and quickly switch several multiple lanes to the right (which is illegal and could cause an accident) and parked on the emergency lane, doing something with his cellphone as if he was texting or sending an email. What have I done wrong on the freeway or intimidate this guy? Is this a road rage or some kind of harrassment? What could he possible do with those pictures he took of me and my car? Has anyone experienced this kind of behavior? It's mind boggling and suspicious...and I was worried.
I'm just an ordinary law-abiding citizen driving an old Subaru Outback wagon which I bought brand new (not stolen). Maybe I'm a "celebrity" and driving a "cool" automobile, LOL!. But this guy driving a brand new pickup truck with no license plate gives me the 'creeps'. Could he be an 'off-duty' police officer? If he thinks I was speeding and following him too closely, he can't even prove a thing. He himself made several illegal things on the freeway mentioned above. I just hope he didn't take clear pictures with his cellphone and that he would just mind his own business and not cause any trouble.

 

[bubba]

Could be :
1. you own a very cool car
2. you are famous
3. He saw you doing something illegal.
4. He was a PI spying on you for someone else.( he apparently got a lot of your information and whereabouts and was calling someone)
5. like the other guy said he thought it was a stolen vehicle.
6. he saw something strange on or around your car

 

[michael]

Driving is a numbers game. Of every hundred cars you interact with (perhaps every fifteen minutes on a lightly loaded freeway) on average one driver will be the worst in a hundred, one will be clinically schizophrenic, 7 will be alcoholics, several will be methamphetamine or cocaine addicts, 2 will have been driving less than a year and 2 will be in their last year of driving. Several will have recently lost a loved one or been fired from their job. 3 will be on probation, parole, or recently released from jail. 20 of them beat their husbands or wives.

That guy was well within the limits of what passes for normalcy in that mob scene.