[jefftk]

> A taxpayer does not have receipt of cryptocurrency when the airdrop is recorded on the distributed ledger if the taxpayer is not able to exercise dominion and control over the cryptocurrency. For example, a taxpayer does not have dominion and control if the address to which the cryptocurrency is airdropped is contained in a wallet managed through a cryptocurrency exchange and the cryptocurrency exchange does not support the newly-created cryptocurrency such that the airdropped cryptocurrency is not immediately credited to the taxpayer’s account at the cryptocurrency exchange. If the taxpayer later acquires the ability to transfer, sell, exchange, or otherwise dispose of the cryptocurrency, the taxpayer is treated as receiving the cryptocurrency at that time.

So you would not owe tax until they supported it (if at some point they do). Whether it's theft isn't a matter for the tax agency.