Well, that varies by cyclist, as you can imagine. Some cyclists obey the law, just as some drivers do. I can't control what other cyclists do, just like you can't control what other motorists do.
There's a lot of confusion between both cyclists and motorists about how to treat cyclists. Laws vary a lot by state (and city). And a lot of people (on both sides) just don't seem to understand that bicycles are vehicles and should obey the laws of vehicles on the road. And be on the road, not the sidewalk (by law in many jurisdictions)
I stop at stop signs and yield to traffic with right of way, and occupy the lane when it's necessary for safety (and get over to the right if not).
I do not stop completely at stop signs if no one is around and I have good sight lines. Bicycles are much slower, have much better visibility than cars (higher, no near-field distractions) and therefore get a much better view of intersection. And they've got a lot more skin in the game if they make a mistake. Coming to a complete stop with a bicycle is almost never necessary for safety reasons. Idaho allows cyclists to treat stop signs as yield signs.
Probably 70% of drivers incorrectly yield to me when I approach a 4-way stop, though. Even after I come to a full stop, and put my foot on the pavement, they'll sit there and wait for me to go. Not to mention the aggressive, unsafe overtaking and other problems that drivers seem to have sharing the road with cyclists.