Data and gear should be mass nouns, like water. You don’t have a water; you have a few drops, a river, a stream, or an ocean. You have water, maybe liters of it, maybe gallons, maybe hogsheads and half butts, but you don’t get a water unless a water is a unit of it in a fixed quantity. People do say things like, ‘Pass me a water.’ They mean a water bottle or glass, always in a unit.
I don’t have a datum; I’ve got a data point. I’ve got gigs and gigs of them. I have good data, bad data, garbage data, and big data.