I suggest the paragraph be more clear on that, then. "We may however receive orders unrelated to FISA, in which case we are legally allowed to challenge the order."
It might be best to be completely forthcoming. Let the customers know that their data can always be secretly read by the NSA with CloudFlare's assistance, even all customers' data, but you challenge what you are legally allowed to challenge. Or say nothing about it. As it is the text implies that the customers' data is better protected against snooping, which isn't possible and most everyone knows that now, so it leads to suspicion.
It might be best to be completely forthcoming. Let the customers know that their data can always be secretly read by the NSA with CloudFlare's assistance, even all customers' data, but you challenge what you are legally allowed to challenge. Or say nothing about it. As it is the text implies that the customers' data is better protected against snooping, which isn't possible and most everyone knows that now, so it leads to suspicion.