What did the 170 citizens detained in immigration raids last year do that was illegal?

If it was illegal, why were charges either dropped or never filed to begin with for the majority of these cases?

If you are open to understanding why people are so upset, do your mind the favor of reading this high quality reporting on the treatment of US Citizens by ICE

https://www.propublica.org/article/immigration-dhs-american-...

If they were only arresting people not in the country illegally and doing it with constitutionally guaranteed due process then you may have a point. But they aren't. They are arresting, injuring, killing people who are exercising their constitutional rights. ICE has no shred of credibility left. They are not making things safer.

I personally know people in Minneapolis (where I live) who's constitutional rights have been trampled on by ICE. ICE is the enemy, all who support them have blood on their hands.