Germany is prosecuting online trolls. Here's how the country is fighting hate speech on the internet.

Dozens of police teams across Germany raided homes before dawn in a coordinated crackdown on a recent Tuesday. The state police weren't looking for drugs or guns, they were looking for people suspected of posting hate speech online. 

As prosecutors explain it, the German constitution protects free speech, but not hate speech. And here's where it gets tricky: German law prohibits speech that could incite hatred or is deemed insulting. Perpetrators are sometimes surprised to learn that what they post online is illegal, according to Dr. Matthäus Fink, one of the state prosecutors tasked with policing Germany's robust hate speech laws.