Liberty can only be taken away if you take someone's liberty away.
Such as murder, kidnapping, stealing, etc.

Forced sterilization is a violation of liberties.

We wouldn't be in this situation if tax-payers weren't paying for welfare.
Paying for their food, homes, schools.
Before welfare if a family had more than enough children, they would starve to death, just the way it should be.
It is highly irresponsible to have children and not be able to support them.

Because of welfare, irresponsible parents have more children than responsible parents. The responsible parents are taxed to pay for the irresponsible parents.