Not sure what the penalties for disclosing an NSL are, but companies sometimes use warrant canaries[1] for this purpose. Notably the one used by Apple disappea

Not sure what the penalties for disclosing an NSL are, but companies sometimes use warrant canaries[1] for this purpose. Notably the one used by Apple disappeared some time last year. [1]: https://en.wikipedia.org/wiki/Warrant_canary https://en.wikipedia.org/wiki/Warrant_canary