Getting hit on by a mental case that would probably settle for anyone (or anything) due to his innate tendency to scare off whoever he looks at immediately is definitely
not on my list of dating achievements, the cause thereof also not being something I would attribute to any part related to myself. Sorry to disappoint.
I'll just ban you myself, who needs Noc?
Probably Germany. Just about anything is illegal over here if you twist the laws just right. (Just about anything is legal if you twist them the other way, too.)
That aside, a quick Google search led me to this:
http://www.theregister.co.uk/2010/08/18/mall_talk/
So... while you won't get a restraining order, it might get you arrested in a certain mall in...
... California. No further questions.
In the style of the German Bureaucratic Republic, you'd probably have to fill out an application form first (then wait four weeks for a rejection, lodge an objection, wait four more weeks, take it to court, and if you pay your lawyer more than they pay theirs, you will win and can talk to the person).
One might argue that this is also a form of conversation, but unlike verbal conversation, it is possible to dismiss written conversation by not opening letters you receive and thus not partake in conversation by reading - unlike verbal conversation, which is impossible to not hear, provided that the unsolicited conversational partner's unsolicited conversation starting utterance is audible under the circumstances you and your unsolicited conversation starting utterance-emitting unsolicited conversational partner are in.
Unlike talking to someone, delivering a letter to a mailbox is also a rather passive way of initiating conversation, entirely leaving the decision up to the recipient - if they are not interested in conversation, they are not obliged to even check their mailbox, let alone take the letter out, or even open it, or *gasp* read it.
@Cantavanda If talking to the person you wish to talk to is not a feasible option for you, maybe you could write them a letter. The benefits of doing so are widespread, including but not limited to your ability to think about what to write and, if necessary, change what you wrote or start over without your conversational partner having read what you had written before, as well as their ability to ignore the conversation attempt by not reading the letter, as illustrated above.
Be careful not to end up stalking them to find out their address, though. Also don't put the letter into their bag when they're not looking, this might make you look like a thief or creep or both.
Giving the letter to them directly also seems risky, as it can be seen as direct conversation initiation and thus bears all the risks of it, as well as the risk of the recipient starting to read the letter while you're still there, which in turn has a plethora of other associated risks.