Today, I was shooting street with a Hasselblad 501CM and a 4/180 lens, a beastly combination, indeed.
Some of the shots were while I was sitting down and drinking fresh orange juice with a old classmate who is jazz pianist and talking about artists and survival. A few frames where taken while we were walking to our parting spot.
I found out that the camera doesn't make much difference when people realise they are being taken photographs of.
People have reacted to my Hasselblad, my Rolleiflex, my Olympus XA, my Holga, my pinhole and my cell phone camera. Some don't pay attention. Some stare back at you. Some few will try to get out of the shot. And the very few will respond with mild aggression.
Sure the equipment makes a difference: the Hasselblad is loud, the telephoto is huge, the retro styled cameras are weird and so on. But it is more the attitude of the photographer: if you show balls and careless indiscretion, if you keep your cool and give them a genuine warm smile as a quiet thank you, most of the times, it is all it takes. When questioned, you reply with honesty that is the beauty of one's face/lines/colors/etc that attracted the artist and that takes care most of the encounters. If one is looking for a fight, well, try your best to avoid it. I never gotten in such a situation myself, though.
A camera is always intrusive and many people will react to it, sometimes negatively. Learn to deal with it.