Generally, because I'm 6ft 1, have a few visible tattoos and am physically fit, guys don't openly disrespect me in the way you described.
For me it has happened more in the past when I have to deal with people in a business sense, like buying something, asking a shop attendant for advice etc. It's like they know they are relatively safe in the structured environment of a business premises, so they think that allows them to act like an a s s h o l e.
I get pretty mad, but although I feel like I could choke the living s h i t out of them, I know I can't do that, so I belittle them outright.
Scenario; Buying a laptop.
me- 'hi, can you tell me about this laptop, the features, brand etc'
them - talks/acts rudely, etc 'yea its good'.
me - looks at them with open contempt - awkward silence (for them)'what experience do you have in computing'
them - oh er, I have a similar laptop at home..its pretty good..i have no troubles with it..er...'
me -(in an obviously heated and forceful tone) 'that's all? so your experience is standing in a shop all day acting like a cowardly p r i c k that's nothing but rude to customers? That's it?? Go get the store manager, I want a word with him about your conduct, and I want to speak to someone who actually knows what they're talking about'.
I have to point out that I'm always friendly to shop staff at first. I never treat them with disrespect first (I've worked in a representative role before, the general public can be a nightmare to deal with).