German Dissidents Jailed

What did the dissidents do that was so bad that jail was warranted?

Seven homeschooling fathers in Germany spent several days in jail for refusing to pay fines that were imposed on them for failing to send their children to government schools.

Homeschooling! Can't get much worse than that, I guess.

As noted in the same article:

some German families have escaped the nation to prevent the state from taking custody of their children.

We are not the property of the State no matter how much the State itself may insist otherwise.

Is this incident a matter of an arrogant State asserting ownership of peoples' children, a campaign against Christians, or are the German authorities afraid to set a precedent that would allow Muslims to homeschool their own children, potentially closing a door to assimilation? All of the above?