People are spending millions on NFTs. But what does it really mean to own something on the internet? — More than a decade ago, Anand Venkateswaran, an app developer and Vignesh Sundaresan, a journalist, met at a canteen in Chennai. A month ago, they paid $69.3 million dollars for a piece of artwork that does not exist, at least in the physical realm. The said piece, titled ‘Everydays: the…