Yes. I hacked it, and they never accepted it. They even tried to manage the media to whom I approached. So just to be clear, I admire Google a lot, they are remarkable, but they are not God.
The story starts in the year 2006 when I was new to blogging and found that ads on blogs could be a way to make extra money. I then got registered to Google AdSense and made their ads live on my blog. It was apparently mentioned in Google’s terms to not click or make someone available to click those ads. That raised an urge for me to understand how their system works.
Fast forward 6 months from then, I found a way to cheat their system. I then wrote to Google about the loophole and they denied. I then contacted media so that they would understand and cover what I have found. Multiple media houses showed me the gate outside and never believed in me. Bangalore's Times of India’s Sr. Reporter however believed me and started exploring, but after some time he also stopped responding. When I asked him, he said, “Buddy, Google is pushing a lot to not to cover it. I told them that even if I won’t then someone else might. Then they told me, ‘we will manage that but you shouldn't publish it.’”
I never bothered that reporter afterwards, as I was able to get what’s at stake and might be any deal they had. I kept on looking for someone for 11 months and then one day I got a reply from DIGIT. They agreed to investigate it further and appointed someone from their team. They took almost 3 months to verify my claim and published a cover story in the November 2007 edition. Here is the PDF of the that article got published:
I later got interviewed by French and Belgian media and got a lot of admiration for what I had found. It later took more than 6 months for Google to come up with a fix.
Edit: It’s important to note that Google remained vulnerable for so long.