I recall some court rulings here in the US that a company could be required to install new software to write log data to disk, once the court found out that it

I recall some court rulings here in the US that a company could be required to install new software to write log data to disk, once the court found out that it was available in memory. This is only a special case of "information which they [do] have in their possession", but shows that that rule goes further than one might think. I am concerned about another scenario. I'm working on a site where people can exchange messages they've encrypted at the endpoints, such that the participants alone have the decryption ability and the server does not (assuming drawkbox is mistaken in some of his claims). Will it be illegal to launch this in the US if the requested law is passed first? Sometimes in tax law, courts have held that because Congress was considering a bill, the taxpayer was on notice that something was going to be illegal, and then the taxpayer was unable to rely on it, even though it was legal when he did it. Besides, USG in recent years has proved to be unrestrained by legal barriers to anything it has demanded.