OBD ,, OBDII, III, OBDIV are all basically CAN bus. Its low voltage serial communications.. They share common set of commands and structures, with each vehicle vendor layering their own "stuff" on top. If you rusing the USB probe off a laptop, any risk is miniscule. (Not enough current to damage anything.) and there are a bunch of proprietary codes for each vendors ECU required to write data. (Its the part people have to reverse engineer to program ecu's with write capability) if its OBD* usually there are a few standard read commands that puke out the standard required data from the ecu to meet the OBD smog reporting requirements.
Hope this helps on the research side.. :)