take a/(one's) pound of flesh

To collect a debt or exact a punishment, especially a cruel or unreasonable one. An allusion to Shakespeare's The Merchant of Venice, in which the moneylender Shylock demands he be paid a pound of flesh that was promised as collateral for a loan. The victim of the incident, while only sustaining superficial injuries, is insisting on taking his pound of flesh from the nightclub owner following the court ruling. Don't get mixed up with those loan sharks. They'll take a pound of flesh without batting an eye.