I think I was talking about the following situation: You deposit some cash to Strike and send it to a friend, say, in the US (as cash). If I understand Strike correctly, the transactions are so fast and cheap, because they first swap your cash into BTC, then send this BTC to the friend‘s Strike wallet via Lightning, where it gets immediately swapped back to cash (in this case dollars) and shows up in the cash tab. Now, this first swap is theoretically a taxable event for the friend (selling BTC) or, when the friend sends you some cash, it’s a taxable event for you.