I'm planning to harass some migrant families because they crossed the border.
Huh? That's kind of cruel. Why do you want to harass migrant families?
I feel they are wrong for crossing the border illegally.
It's wrong to harass families that are looking for a better life. By doing this, you are giving them the impression that people like you are hateful. This will cause them to judge people that look like you as mean and hateful.
They're the ones who broke the law and they need to obey the laws to enter the country. I'm not the bad guy here.
It seems like your issue should be with the government and not with the people crossing the border. Perhaps try speaking to one of your political representatives about your immigration concerns. Harassing an innocent family won't help anyone.