There's this girl I used to talk to fairly often, for years, we were schoolmates and when we went separate ways at college, we still remained in contact often.
At someone point she started dating a guy from her school, which we'll name D, a highly possesive and violent individual that, for whathever reason, one day decided it was a good idea to start a difamation campaign against her.
The exact reasons that led him to do this are not clear to me, but it appears to be an overexageration and, in any case, the effects that this event had are impossible to justify no matter how you see it.
The assault campaign included sharing text messages, as well as facebook messages out of context. Personal information as well as intimate material on a rather extensive basis.
D also actively sought to drive other people away from her until eventually he succeeded in turning a lot of people from their school against her, which only worsened things. People she didn't even talk to from the school started texting her as well, and many people eventually hated her altogether, some truly disgusting situation if you ask me By this point it should be obvious that the relationship was long over, and maybe more than one of you is asking "why didn't she act against the individual?"
Turns out she didn't because of fear of retribution of some sort, as if she was afraid that the guy would act physically against her. By this point she had developed an anxiety disorder that pretty much disabled her from doing many of her usual activities.
So she did pretty much the only thing the thought she could do: leaving the city
She went away and hoped to start over again, but the harassment didn't end there. Months after she had moved, she continued to get text messages from an anonymous source which is presumably the same individual insisting that she should apologize to him, and that it was all her fault.
Either way, my question is as follows: which is the best way to proceed in this case? Is there anything I can do or say to her? I've been thinking this lately since it doesn't appear to stop.
Keep in mind that since this whole situation started (that is, D started behaving like an ass) to this point it's been already more than a year, so it's quite a long time.
Any comment or question about the situation would be pretty much appreciated, and sorry for the tl:dr