I personally beleive the owners probably knew that Performance Enhancing drugs were being used as early as the mid 90's...But they turned a blind eye to it because MLB was in the process of recovering from the strike and the canceled world series. The Sosa/McGuire Chase of '98, at the time, was credited with saving the game after the strike and also ushered in an era of increased offense as well as ticket sales now called the "steroid era".
Now the owners are throwing bonds under the bus so they can act tough on steroid after letting it go for the better part of a decade. However, the owners did not initiate the drug testing program currently in place it was congress. If not for congress the owners probably would still be ignoring the large steriod using elephant in the room.
Let me ask you this if a bunch of truck drivers were on amphetamines so they can drive longer hours and the head of the trucking company knew about it and did nothing wouldn't he be considered just as guilty. I'm not saying bud or any other owners knew steroids were going on, but it seems like they tried very hard to not know it was going on so they could have denyability later.
Baseball players who cheated and took steroids should be punished severely, but let's not overlook who made the most money from the steroid era, the owners. Shouldn't they be punished as well?