When Alexandra Wallace recorded her rant about Asian students using cellphones in the library at the University of California, Los Angeles, she was alone, speaking to her computer.

But since she posted the three-minute video to YouTube, Ms. Wallace, a third-year political science student at U.C.L.A., has achieved a sudden, unwelcome celebrity: her video has been viewed by millions of people, and she has become the subject of nationwide condemnation and the catalyst of a debate about racial intolerance and free speech.