Firstly:
No one will report you for sending them gold, if somoene sent me a high amount of gold, its tough t!ts, the gold is mine end off.
Secondly:
yes you can ask for it back, but they can just ignore you and that would be the end of it. Then if you make LOADS of alts, they can report you for harassment, and blizzard GM's cant do anything.
I did the same thing once, luckily it was 10g, thought i sent it to my character but i forgot the last letter was an "á".
I ticketed them and they say they cant do anything, only to mail the person and ask for it back.
Thirdly:
They usually ban the "bank" char, and then ban your account, and all the characters on it. Not innocent people.
Anyway i commend you for trying, it was good thinking, but blizzard dont work like that, and people dont report other people for sending them gold
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Take care....