While I dont like to be too cynical about these things. Reputable companies are as likely as any other to be involved in shady business practices. In a one person company you only need one person to be honest, whereas in a large business any level of manager can push their underlings to do wrong.
Here is how a large number of reputable oil companies cheated their customers in Connaught.
http://www.irishtimes.com/business/galway-oil-cartel-enforcer-was-prime-mover-1.1026360
Here is how a large number of reputable oil companies cheated their customers in Connaught.
http://www.irishtimes.com/business/galway-oil-cartel-enforcer-was-prime-mover-1.1026360