1. Literally, to be coated with tar and bird feathers as a form of public punishment and shaming (one that is no longer carried out). The thief was tarred and feathered in the public square before being paraded through the town strapped to a wooden cart.

2. By extension, to be severely criticized, reprimanded, or excoriated, especially in a public and humiliating manner. After this economic collapse, everyone is demanding that the heads of the bank be tarred and feathered, but I'd be willing to bet that they'll just get a slap on the wrist.