It's probably instances of vehicle observations. If they observe the same, say, ...

		foota on July 10, 2018 \| parent \| context \| favorite \| on: A California mall operator is sharing license plat... It's probably instances of vehicle observations. If they observe the same, say, million cars a day for a year that's ~400 million observations right there. If it's multiple times a day you could quickly reach 5 billion.