In most cases I've personally witnessed (I have an RTL-SDR decoding ADS-B transmissions in the vicinity of my home) the interesting aircraft (e.g. fighters) are

In most cases I've personally witnessed (I have an RTL-SDR decoding ADS-B transmissions in the vicinity of my home) the interesting aircraft (e.g. fighters) are not operating an ADS-B transmitter at all, so there's nothing to hide. Some sites (adsbexchange.com comes to mind) do not filter anything.