"...We are still considering legal action against them on this field..."
For what, exactly? Sounds like sour grapes to me.
Either this 5 minute delay is an internationally legal requirement, or it's not.
If the powers that be deemed our hobby as a security risk, they'd pretty soon say so and ban any use of it at all. Five minutes either way ain't gonna make any difference. It seems nonsensical to me that traffic received over a network is considered more of a risk than something received live, locally - the reverse is more logically true. Anyway, the simplest expedient for the authorities would be to encrypt ALL ADS-B transmissions and modify legal equipment accordingly, in which case we'd all be b*ggered.
And it's quite simple to re-transmit live traffic now, for the benefit of others, simply by utilising third party recording software (as is the case in Sao Paulo).
I'd be in favour of getting everything we can, while we can - once the precedent is established it would be far harder to back pedal.
DC