I only rang the gong twice. The second time will be my last. The first time it granted me a measly amount of technology when I already had a couple hundred thousand.
The second time was a rude surprise. It took away ALL my food. I had over 30,000. While I haven't had any trouble with that farmer glitch others are having (mine divide their time equally between watering and fishing), and I had plenty of farmers to recover without anyone starving, I got dizzy grabbing people away from watering and ferrying them over to fish.
The Gong of No Wonder the other villagers smashed it and hid the pieces.