If you are using them in the US to transmit at their full power in a point-to-multipoint system, they are not legal. They would be legal for a point-to-point s

If you are using them in the US to transmit at their full power in a point-to-multipoint system, they are not legal. They would be legal for a point-to-point setup, since they achieve their high EIRP due to high antenna gain (as opposed to high output power). But also due to that high gain, they're not really useful for anything but point-to-point (think backhaul between buildings). You could also use them legally and usefully as a client (pointed at an AP) if you turn the power down so that the EIRP is 4 W (36 dB). You'd still benefit from the high antenna gain in the receiving direction (though not in the transmitting direction, which includes TCP ACKs).