[edj]

Exactly. Without a doubt there was a literal conspiracy to undermine urban mass transit during the 1930s and 1940s. Firestone, Phillips, Standard Oil, and GM were all convicted of conspiracy, for Pete's sake.

http://en.wikipedia.org/wiki/General_Motors_streetcar_conspi...

[kahirsch]

They were convicted of trying to monopolize sales of buses and bus parts, not eliminate mass transit.

[loup-vaillant]

Bayesian evidence. Being convicted of a crime is strong evidence that you might have committed other related crimes.

If those companies where convicted of collusion, then it is very likely they conspired about more than a little monopoly.