I got "touched" by the same person.
Troll: "Please help me translate some highly personal documents - not meant to be shown to anybody else."
Me: "OK, I'll take a look"
Since the documents were mainly specifications, I pumped out a translation
Troll: "Thank you so much. Since you did such a great job, here are 6 more pages for you to translate"
Me: "You know, I think I've already done enough translation for free for you, better you give these pages to a professional translator"
Troll: "I don't see why you can't help me!"