Telepathy: Telepathy (or rather, techlepathy) is a somewhat limited faculty, as described under Psychic Powers. Being essentially a way to transmit neural gestalt information over WiFi, it is an excellent messaging system, complete with the ability to transmit images, emotions, information constructs, and other non-verbal information, and communicate broadcast/narrowcast, local/distant, private/conference, etc., etc., and even to synch up well enough to form a conflux (see: Mental Fusion).
It doesn’t, however, let you overhear people’s thoughts (unless they’re sloppy and accidentally broadcasting, which does sometimes happen), go in and pull thoughts out of their heads (you want a SQUID for that, or a mind-state reader of one sort or another), control minds (although you can inject the same memes as you can over any communication channel), or enable the rest of the assorted magical aids and attachments (dream travel, astral projection, and so on and so forth). It’s also, being EM based, limited to the speed of light.
Since it’s harder to fake all the sidebands, a telepath can sometimes be something of a Living Lie Detector, but reliability in this role still isn’t great, and you are almost certainly better off with a regular mechanical alethiometer (which uses a SQUID).