We need a virus, that emulates encrypted communication and is otherwise harmless.

In a certain way, that is a brilliant idea! Generate a random key, encrypt a bunch of random data with it (or maybe even just generate a bunch of random data), and send it to a few of your contacts, who immediately discard it.

But I think such a feature would better implemented at the OS level! :)

But surely in that case we would all demand to be able to inspect this data that is being generated and shipped on the devices we "own".

Let's assume the OS is FLOSS software and includes a daemon that sends random data to other devices to be encrypted and discarded randomly.

But if you take the laptop outside, at full moon, and dance naked on the hillside around a fire, singing "SudOh how I want to be free, baby", you can overcome those settings. There is absolutely no reason to be enraged about the evil. There is even a tech-community valve installed, see instructions above.