[xwiki-users] polls and rights

Hi, I'm planning to do the following: Each document based on a certain template autmatically gets it's own standard poll. (No customisation.) Each user visiting the page can vote. Having looked at the polls application and played around with templates a bit, I think I know all the ingredients I will need. I have one problem though: Anyone who votes needs write permissions on the document that saves the votes (whereever that may be). If I'm not mistaken that means anyone who can vote theoretically can manipulate voting data by accessing these objects directly. Is there any way to secure this against manipulation a) from users who can vote? b) from the user who created the page? Probably that question is equivalent to: Is there a way to let users save changes on an object only via a script while hindering that very same user from editing it directly? Any hints are greatly appreciated!