i shank my overheads into the back fence, more often than i like to admit... don't intend to hurt anyone, and usually don't hit anyone when i do, but it happens... and definitely happens alot more at the intermediate/beginner levels.
"fh lasers from NML"... when i'm playing good doubles players, or when i'm playing well at net,... i am absolutely hitting&getting balls hit at me at full RIP, aimed usually/ideally at my right hip.... sometimes it goes higher than I or my partner want...
if you're not comfortable getting those shots at you, accidental or otherwise, DO NOT COME TO NET.
that said, if it's a social game, or if net person is not very good, and clearly can't defend/protect themselves, i won't go at them when i get a sitter... but if they are actively poaching at net (as they should be IF they were good at net), they need to expect to get hit from time to time.
when i'm playing folks that are hitting a bit faster than i'm used to or if my partner's serve sucks and i'm constantly getting hit... i move back.
side note i've been hit plenty of times... usually in the posterior chain (back, hamstrings, calves) as i turn away... .had my glasses knocked off (glancing blow from racquet), and have been hit clean in the back of the head off a rec-level overhead... stung (but compared to getting hit in the head pointblank&knocked out by a soccerball while in goal... no comparision)