It is exactly the mistake Europe made, ironically in handling Germany, over war reparations in 1919.
Decades after Cannon's abuse, Chicago established last week a reparations fund for police torture survivors.
Typically, the mechanisms involved include retribution against perpetrators through the criminal justice system, and reparations to victims, including the return of property, financial compensation for suffering, or symbolic gestures such as overturning unjust convictions – as well as simply saying sorry.
It is not easy to even begin to quantify what constitutes just reparations for horrors such as slavery in America, apartheid in South Africa and the Nazi Holocaust in Europe; yet that is the ethical question raised when the past pushes its way, uncomfortably, into the present.
The actor, now playing a slave owner in the film 12 Years a Slave, has in the past acknowledged his ancestors' slave ownership, and revealed that his mother once urged him not to use his real name professionally for fear of becoming the target of reparations claims by the descendents of slaves.
In fact, it's not so much an artistic compromise as an artistic surrender, with punitive reparations.
Leigh Day is currently preparing for a particularly titanic case; representing the Caribbean nations in a claim for reparations for slavery.
On Monday, at an event titled "Reparations Not Black Sites" in downtown Chicago, demonstrators continued to push Emanuel and the city to take up an ordinance that would include further payments to victims under Burge as well as a formal apology from the city, community centers and a requirement for Chicago public schools to teach the history of police abuse in the city.
Local civil-rights groups have long sought reparations relating to the notorious practices of Burge, the former Chicago police commander who was released from home custody this month and is estimated to have cost the city upwards of $100m stemming from settlements and judgments in civil-rights cases.
There have been legal reparations, insufficient of course, but symbolically incisive.
Citing its work that dates back to a 2013 reparations ordinance linked to torture by the notorious police officer Jon Burge, the human rights group Amnesty International sent its own letter about Homan Square Wednesday to the justice department official behind the damning Ferguson inquiry.
