>4. Moreover, arrange it so that subpoenas are published before being read, so that if you get a National Security Letter, you would not be able to comply with the non-disclosure requirement. Another way to go about this may be to only open subpoenas in a public forum, preferably with journalists present. Try to consult ACLU/EFF lawyers about this particular issue.
I can't imagine this working more than once, the goverment can just verbally inform you of the non-disclosure requirement when they deliver any future documents in person.
It working once is enough, provided you're the first person it occurred to.
In Jujitsu, that's the way it works. You create a new technique, or rediscover it, you get one free shot at Sensei, and then it doesn't work the same anymore.
I can't imagine this working more than once, the goverment can just verbally inform you of the non-disclosure requirement when they deliver any future documents in person.