The following section in the terms of service would apply here:

Under no circumstances will Subscriber use the Network or the Service to (a) [...] (b) harass, threaten, stalk or abuse any person or party, including other users of the Network,

Also the "be nice" section of the help center outlining the code of conduct on SE has a relevant section:

Harassment and bullying. If you see a hostile interaction, flag it. If it keeps up, disengage — we'll handle it. If something needs staff attention, you can use the contact us link at the bottom of every page

In short, doxxing is against the rules and if you see an instance, flag for moderator attention and we'll deal with it.

The following section in the terms of service would apply here:

Under no circumstances will Subscriber use the Network or the Service to (a) [...] (b) harass, threaten, stalk or abuse any person or party, including other users of the Network,

Also the "be nice" section of the help center outlining the code of conduct on SE has a relevant section:

Harassment and bullying. If you see a hostile interaction, flag it. If it keeps up, disengage — we'll handle it. If something needs staff attention, you can use the contact us link at the bottom of every page

In short, doxxing is against the rules and if you see an instance, flag for moderator attention and we'll deal with it.