Premining has a very simple technical definition: premining is the act of hard-coding the distribution of coins into a distributed ledger prior to the ledger's

Premining has a very simple technical definition: premining is the act of hard-coding the distribution of coins into a distributed ledger prior to the ledger's public debut. Unfortunately there are plenty of prolific high-ranking members of the cryptocurrency community who accuse coins which are explicitly NOT premined by any technical definition, of being premined. Many of those coins can only be accurately described as "ninjamined" or "cripplemined" or "instamined". Admittedly, some do consider ninja/cripple/insta-mining as being on the same spectrum of a premine, in that the end result is essentially identical. But this is a bit of a slippery slope, in that it opens up all coins to "premining" accusations, and then the simple technical definition above loses all meaning. For example, many have speculated Satoshi Nakamoto must've been running a network of 20-50 Bitcoin mining servers prior to the launch of Bitcoin, given the blockchain evidence we have of Satoshi's hashrate maintaining consistency from Block 0 onwards. Is this a ninjamine? If a ninjamine = a premine, then Bitcoin is arguably premined by this definition. So you can see it's not very meaningful to diverge from purely technical definitions. Ethereum epitomizes the technical definition of premining: their ICO raised BTC on Bitcoin's blockchain, and the founders of Ethereum initially hard-coded all ETH owed to their Bitcoin-based ICO backers into their blockchain prior to its public debut. The Ethereum Foundation premined still more coins on top of this. But this doesn't necessarily mean all ICOs are premined, although I don't personally know of any ICO which doesn't exhibit some amount of premining; at minimum the project founders usually scoop coins in a premine on top of an ICO, Ethereum-style.