If the harassment is happening on bungie.net, please report it to the Ninjas to take a look at. If it's a message such as a PM, you can directly report that message from the message options; otherwise, you can speak to any Ninja about it by contacting them:
https://www.bungie.net/en/Forum/Post/255429770/0/0
If it's happening on other platforms outside of bungie.net, unfortunately there's nothing Bungie or their moderators can do. You would want to reach out to that platform support to report them.
I also suggest you guys change your account credentials and enable 2FA for extra security if you haven't already.
https://www.bungie.net/en/Help/Article/12718
English
-
As far as I'm aware the actions in bungie.net is limited to looking at our activity through it and kicking people from our clan when they gained access to one of our admin's accounts.
-
Then all you can do is make sure all your admins secure there accounts.