I'm sure if you consumed enough nicotine/caffeine on the job to seriously impair your judgement, it'd cause you HR problems.

I've seen a number of people over the years who would take smoke breaks nearly every hour of the day. That doesn't necessarily impair judgment, but it may have an impact on performance. In theory this is something on which you can crackdown, but it doesn't always happen.

Actually it significantly boosts my performance, which is why I do it the first place. (Obviously if you were hiring e.g. a surgeon, whose job requires several hours entirely without interruption, that would be a different story, but few IT jobs have that requirement.)

But nobody said "enough alcohol to seriously impair your judgement," rather we were talking about any alcohol at all.

That's not what I understood. steverb said, "an employer that doesn't mind how much alcohol is in your bloodstream"

i've worked at and seen plenty of places where they drink beer at work. usually it starts around 3 or 4 though, not in the morning. this is both california and the east coast.