I think it kind of defeats the point. You could learn online on your own, so all you're doing is getting a piece of paper (which you hope leads to a job) out of the online college. I took a couple of online classes from my physical university, and didn't end up learning much from either of them despite getting good grades. It simply wasn't the same as being present at a lecture, taking notes, or listening to a class discussion (even if I was afraid to ever participate). The TV-based class I took was a similar experience, not being there dulled things. Makes motivating yourself more difficult as well when you're not there in person.
It's not as though going to a physical University requires social skills. I got through four and a half years without ever getting to know anybody and virtually flawlessly avoiding conversations. There are so many people that it's easy to be alone in the crowd and nobody remembers you. ('Course the amount of money it costs is a big issue.)
Needless to say there are a ton of scams in the internet education field as well, where your diploma would be worth less than the paper it's printed on. (I recall a fun article where a cat got a diploma from an online "university.")
As for the University of Phoenix, it's not a scam but be sure you're not just listening to their marketing department. It won't have the same value as a traditionally-earned diploma in the eyes of most employers:
(note the stats on what employers think of online degrees)
Note that I personally think the University of Phoenix is the scum of the earth due to all the pop-up/pop-under advertising they subject me to on the internet.