It is indeed immoral. It's also SOP in the American office, both public and private sector. It's pretty much SOP in most American workplaces, period. Especially for salaried workers. Hourly workers get a shitty deal, as well, but in different ways. (Ex. Most hourly workers are scheduled for 30 hours/week so they don't qualify as full-time, and thus don't qualify for benefits, vacation time, sick time, etc. Some will refuse bathroom breaks and lunch hours and require employees to work straight through for 8 to 16 hours (16 hours is the most you can legally work in a 24 hour period). Less reputable employers will have employees clock out at their appointed time, but then continue to work. These are often the same employers who will lock their employees in to ensure they can't leave the building during their work shift to take a break. Or, you know, escape a fire.)

Basically, American workplaces suck as a general rule because our culture has a totally fucked up sense of priorities. Also, we've beaten our unions into practical non-existence, demonized them to near-pariah status, and bad-mouthed every positive gain they've fought for on behalf of the American worker. All while cheerfully swallowing the self-serving lies propagated by corporations to turn the American worker into a serf.

Welcome to our hell.