When is it ok to contact the borrower, as the holder of a NPN?

[Joseph Atkin]

I'm very new to the idea of investing in notes generally, and I have a question regarding non performing notes specifically: 

I feel like I heard/read somewhere that it's not legal (or not ethical?) to directly contact the borrower of a non performing note to attempt to get the note re-performing. Is what I think I heard/read accurate? If so, how does one indirectly/legally contact the borrower to try to get the note re-performing. 

If it's not accurate, is there any nuance to how one should/shouldn't contact a borrower that I should consider? Or is it totally fine to contact the borrower as the new holder of the note?

Thanks in advance for any guidance/help.