All of the above and then some, often peers, plus, most any group of folks in positions of 'authority' ... sometimes in overt ways, often more subtle and covert ...

Now, as for your certainty that none of the folks you know abuse others, how would you know, unless they shared it, something many are unwilling to do ... so perhaps the signs, in your circles, are kept low key ... can't know your circumstances, but i suspect it is appreciably more present than you observe.

namaste,

zy