Do you know the Strassenverkehrsamt provides an online, free of charge and anonymous plates numbers identification service ?

It's called eAutoindex, here it is:

http://www.stva.zh.ch/internet/sicherheitsdirektion/stva/de/StVAfz/FZindex/FZeindex.html

you have just to prove that you are a human thruogh a "captcha" and you are in ! Give it a try with your plate number; I did it. 

It returns name and ****ADDRESS**** of the car plate owner ! ! ! !

Everyone can use his/her own imagination on how these information can be used by somebody who spots you in your car and notes down the plate number ...

Scaring isn't it ?

OK, now that you are scared here is the solution:

http://www.stva.zh.ch/internet/sicherheitsdirektion/stva/de/StVAfz/FZindex/_jcr_content/contentPar/downloadlist/downloaditems/gesuch_um_sperrung_d.spooler.download.1301570219644.pdf/ZLGE_HASPE1007.pdf

just download the pdf fill your data & car plate and send it to the STVA; your data will not be anymore avaialble through eAutoindex (I did it and it works)

Ciaociao

Fabrizio

PS: I don't know if other Kantons motor offices do the same ... maybe ... probably ...