If someone knocks on your door about vaccines I suggest taking out a piece of paper and asking for their name and address with your pen in hand over the paper. Say something like "Before I speak to you I need to know your full name and complete address for our database." Hopefully this will make them aware how creepy it is to go around making databases of people. If they refuse to give your their full name and PERSONAL home address (not organization or headquarters) just close the door. Edit. Also then ask to see their drivers license and take a photo of it. Other possible responses "I am Jewish (or I have Jewish friends) and I don't participate or talk with people making lists for the government." Or " What Nazi or Communist group are you working for because only Nazis or communists make lists of people." Or say " Someone already came by and got my information" This is presuming you even answer the door at all which frankly is rarely advisable in any case today unless you know the person or they called first. Does anyone open their door for strangers? Why? And of course only if these answers are true. No one is suggesting you lie to a government official which might be illegal. Edit. Also don't be hostile. Its just going to get you on a worse list. Its far better to make these volunteers realize how bad what they are doing is. Most will think they are helping. Better to make them think and wonder if they are participating in some future genocide or might have some personal responsibility or liability for future results of their actions. Then they might stop knocking on doors right then. If they can't get enough volunteers this will stop.