There was some discussion of this over on Reddit. I didn't see evidence of it, but the claim was that this had already happened. I'd be curious if someone had some examples of it in the wild.
This is probably a good lesson in general for intelligent malicious actors. If you have an exploit that works, it's important that you use it rarely enough and against the right marks that the loss doesn't enter the collective consciousness as a malicious attack, but simply as an individual or systemic failure.
And for those of us who strive to be constructive and defensive actors, it's an important lesson to remember that sometimes malicious actors disguise their actions as amoral bugs in the system. Regular random auditing of the seemingly mundane is an important tool to uncover these kinds of exploits.