Mind-Readers

If people can/could read minds, what thoughts would they read? I personally always have multiple things going on in my little noggin. So how do/would mind-readers sort them out? I imagine this to be quite a difficult task. Are/Would they be able to pick and choose which thoughts they receive? Or is/would it be random, completely by chance? Or do/would they hear it all, every last tidbit of wacky thought? Perhaps it is/would be similar to a google search. If a mind-reader were to be curious about what the thoughts of an individual were concerning spaghetti at a particular point in time, they would simply search for "spaghetti". Also, then can/could they turn it off? Or are/would they hear the never-ending thoughts of those around them? This whole idea could get rather complicated. As much as I'd like to know what someone is thinking at times, I'm glad I don't have to deal with such dilemmas.
This is what I think about instead of studying for the final exam I have in little over an hour.