Supercuts is being sued for prohibiting Spanish in it's stores (in the interest of full disclosure, the author of PoliticsBlog gets his hair cut there, and will at some point today if he can summon the energy). While Supercuts denies this is their policy, let's take the allegations at face value.
Have you ever been in a business where employees were speaking a different language around you? Remember the Seinfeld episode where the Korean women who did Elaine's nails were talking about her? That's how it feels; uncomfortable. If Supercuts has an "English only" policy, they should defend it. Other companies should follow suit.