Retailers of all sizes worry about operational challenges of dealing with different tax laws in every state.

Companies had contested the states formula for calculating taxes.

Companies had contested the states formula for calculating taxes.

Investors say they were harmed by effort to drive benchmark rate down.

Investors say they were harmed by effort to drive benchmark rate down.

Case involved Colorado law that imposes reporting requirements on internet retailers.

Case involved Colorado law that imposes reporting requirements on internet retailers.

AIG, BNY Mellon and BB&T unit sought to save $1.5 billion.