Well only against the rules b/c the substances happen to be deemed ILLEGAL by the United States government. But what about other supplements that have NOT been deemed illegal in a court of law? Those too give players a supposed 'unfair advantage' but are not prohibited in baseball b/c they are not against the law.

Again, if we consider Mac and others 'cheaters' who are thus ineligable for the hall, then the guys who steal signals, scuff balls, and cork bats are also cheaters who should not be allowed in the hall. This will make for a VERY small hall of fame.

Personally I think performance enhancing drugs can by logic only slightly enhance performance anyway, thus those who take them are not cheaters in the true sense of the word(as opposed to a pitcher who alters the ball). These supplements are a common part of our culture now and ALL athletes consume them. Unfortunately for Mac and Bonds, they took the ones that are illegal. This makes them law breakers in the eyes of the US legal system, it should not make them cheaters in the eyes of baseball.