Uh, I have some things I'm not allowed to do with mind control/reading/writing (compelling or implanting images/speaking/flashing images/etc. through minds) powers even I listed (SEE-
What Bay-12ers can no longer do in a RPG thread).
That aside, I have no intention to invade people's minds. Kinda breaks a spiritual level of privacy. Plus, mind reading would be more like shared memory, kinda like how twins, like-minds, or the mythical soulmates can synchronize their thoughts, even when they're not aware they're even doing so. I would imagine that reading thoughts can be photographic (images coming to mind), words (literally reading thoughts, similar to photographic), and inner-speech (the most inside voice which is only audible in-mind (CAUTION: Minds tend to lack "inside voice". They could get loud. If reading or getting photo-flashes and etc. as a safety precaution, please bring with you at least several cc's of brain bleach.)).
If I had reader abilities, I would prefer it to be selective, and up to maybe a small crowd as a limit to retain sanity and comprehension. After all, by my definition, you're sharing minds, and you can only process so many sub-thoughts at the same time.
In any case, I like to encode my thoughts in a sense that I come up with my own language or context system (or make up a fantasy-like alien language; or learn to speak in tongues as a filter). Other times, I just run a crap-ton of random thoughts (marathons of TVTropes, SCP Foundation, and so on works wonders here). And sometimes, I would just think, after thinking randomly for long enough, scare a reader by thinking "I know you're reading my mind. Cut it out or face the consequences for trespassing.", by then I just consdense numerous thoughts at the same time or think up something so nonsensical, not even being high or tripping out would make any sense of it.
None of them have any meaning, but having others, if any, try to figure it out would be both funny to watch, as well as a way to pinpoint a reader. Confuse the hell out of them, and you'll find them.
I think if you were to read my mind if I were not in paranoia mode, my mind would be surfing the internet (or revisiting past visits) or you'll be hearing a bunch of music playing in my head as if I have an MP3 player going off. Or see me coming up with all sorts of random things that, provided the ability, I would want to do or add to certain games (or add to real life).