1) Create a FB page featuring not-too-offensive content that attracts people who believe in 'white g*nocide'.
2) Accumulate a few 1000 followers.
3) Let FB do the dirty work of finding responsive people who are similar to these followers ('lookalikes').
1) Compile a list of a few 1000 emails, phone numbers or device IDs of people who believe in 'white g*nocide' (via websites, adtech, data brokers,…)
2) Upload to FB via 'custom audiences'.
3) Let FB do the dirty work of finding similar people.