A number of ways. Googling your name to get your Facebook or Instagram account, checking against any other place you may have identified your race (eg. SAT), an interview, someone ratting you out, etc.
Yes, and since it’s not a court of law, they don’t really need indisputable evidence. More than likely though, they will just ask you to verify and confirm the information, which you most likely cannot do.
Anecdotally I have. Elizabeth Warren comes to mind, but I think that was just her teaching bio. Also, race is more than self-identification.
Because race is considered to be an immutable characteristic.
I suppose you could do all that for the marginal benefit it may provide in very limited circumstances, but you would be much better off just spending that time becoming a more sought after student.
Or if you are just committed to being a dirtbag, there are more effective and much easier ways to cheat. You can falsify and emboss a fake transcript. You can claim you played multiple sports well or that you did more extracurriculars. You can locate former grads of the school online, and claim that you are related to them on your app. You can bribe someone to take the SAT for you. The point being that if you are wiling to lie, cheat, and steal to get into a college, there
Why is it obnoxious? Do you think being an URM has an affect on your life? If so, why shouldn’t colleges attempt to account for that in addition to trying to achieve diversity.