Try convincing a physicist that ms means millisecs and mS means milliSeconds. Casually remind them about the difference between bits and bytes and lament the unfortunate fact that textbook writers still don't give enough respect to the "forgotten units". Let the doubt sink in just a little bit.
http://images2.wikia.nocookie.net/__cb20100726071250/xkcd/im...
SI units are not capitalized unless they are someone's name, such as Pascal (pressure) or Newton (force) etc.