Go to a public area and visibly record people. Particularly while talking to them. You will annoy a lot of people and some will act with hostility (especially i

Go to a public area and visibly record people. Particularly while talking to them. You will annoy a lot of people and some will act with hostility (especially if you don't frame it as some sort of interview). People don't like it when nobodies are filming them, even in very public spaces. For some reason they are ok with CCTV, despite that not being much different (I do recognize that cctv is typically recording a general area and isn't always HQ)