on't get me onto golf balls as we used to live next door with a boundary wall running along the 13th par 5. On average when golf was being played anywhere between 30 and 50 golf balls per day would end up on the property. There was some close misses like one landed next to me whilst I was in the swimming pool.
Holy shit that's a serious pain in the arse! and dangerous too..
You could probably sell those thousands of balls, especially if there are any decent ones amongst them, which people would pay €1 each for second hand..