The doctrine was used by the $PLC to successfully sue Tom Metzger and his white supremacy group.
Some skinheads had murdered a defensless black man and IIRC the skinhead scum had no direct connection to Metzger's group except to have been aware of the group's public rantings.
Another case involved a conservative activist and former major general in the U.S. Army sued the AP, at al for falsely reporting that the general led a mob of violent racists on the campus of the U. of Mississippi. The general won. But the case was appealed all the way to SCOTUS that ruled that AP, et al did not intentionally make a false report. They simply made an error.