Instead, I suggest you consider using a carrot and stick approach. Prepare signed and unsigned business cards that contain the following message.
- Unsigned Card: "Please respect my privacy. #RealFansShowRespect".
- Signed Card: "Thank you for respecting my privacy, as a token of my appreciation here is an autograph and my personal contact information."
When approached by an intrusive fan give them an unsigned card without speaking to them THEN IMMEDIATELY seek out someone (ideally someone around your age) in the immediate vicinity who is showing respect. Reward that person by politely engaging them in conversation and providing them with a signed card (if they want it). You could say something to the effect of "Hi, you may not know or care who I am, but just in case you do, I would like to give you this (signed card) this as a token of my appreciation for showing respect."
You shouldn't give out more than one signed card per incident because it will devalue the message that is conveyed.
(Note: the contact information you provide can be separate from your everyday contact info. - but keep in mind you can learn a lot from these people and the reward for respect should be legit.)
It may take a while, but eventually people will get the message - especially nowadays with social media.