To be technical "harassment" is not in the rules. (Though, to be even more technical, "Posting personal information", which is pretty much a prerequisite to this sort of harassment, is, so six-of-one/one-half-dozen-of-t'other.)
Veering off-topic a bit, but bytes are cheap, so "oh, well"--
I'm not just saying this to be contentious-- it just struck a rant nerve. The scattershot, half-unspoken nature of The Rules has been a peeve of mine for some time (since "NP" came about). The people running the site should (or should have, really) sit down and bang out what rules they want, then put that on one single page, replacing all others, and call that The Rules. That'd at least let people know where they stand, and stop the seeming indiscriminate nature of things like shadowbans.
Instead, as it stands, there's a mish-mash of offical, semi-official, and unspoken sitewide expectations, and that's not even counting sub's rules. There are the rules, which are so out-of-date as to be worthless, and are often treated as such. There is reddiuqette, which is presented as more of a "friendly guideline", unless someone's citing it as "the rules". Just today, I learned there was actually a completely separate User Agreement in smaller type at the bottom, and then you've got things like No Participation (np) links-- a clever hijacking of Nepalese localization, IIRC-- for which RES amusingly pops up a box[1] saying that violating NP is against the rules, which it links, but which doesn't mention anything at all that would reasonably apply to NP.
I agree with some of the clean-up Reddit is trying to do, and a proper no-personal-harassment policy would not be too terrible a restriction. However, from my perspective, it seems oddly like they're steadfastly refusing to take the simplest, most obvious first step to deflect criticism, that of actually changing the rules before implementing them.
[1] RES message when you go to an NP link: "You came to this page by following a NP link, so you may be interfering with normal conversation. Please respect reddit's rules by not commenting or voting. Doing so may get you banned. Find out more"