Well...on the one tentacle there is precedent, in Starfire you could get tech info by close in scans. Also, knowing that something could be done, and actually seeing it done, ought to give a leg up to R&D.
However, on the other tentacle, I agree that this just seems too powerful. I was thinking about suggesting that the scanning might not work if the scanned unit's shields were up?
There are several reasons for this rule, some to do with realism and some to make gameplay more fun.
1) There needs to be some advantage to getting detailed scans of alien ships
2) It gives races that are badly outclassed a chance to catch up over time if you can get the data to a laboratory.
3) It creates a reason for recon missions to learn about the potential enemy (US Subs lurking in the Barents sea, U2 missions over the Soviet Union or Russian Trawlers in the Atlantic)
4) It creates tension between races and a potential reason for conflict, which always makes things more interesting
There are also some reasons why it is perhaps not as unrealistic as you might think. All the major powers on Earth are relatively equal in technology and one of the major reasons for that is they spy on one another, steal technology and closely monitor each other's hardware. In other words, once someone develops something, it doesn't take long for other countries to get it. In Aurora you can get a maximum of 10% from one successful scan (and usually less than that) so it takes time to get enough information to gain a technology. That time can be thought of the time required to assimilate the information.
With regard to shields. At the moment, putting your shields up just makes it easier for the enemy to learn about your shields
. However, making it harder to scan a ship with shields up (apart from the shield technology), does make sense. Therefore for the next version at least 1 point of active shields will prevent the following:
General scans of internal systems using active sensors
Scans of engines using thermal sensors
Active shields will not prevent:
Scans of active shields using EM sensors
Scans of active sensors using EM Sensors
Scans of active ECM and ECCM systems
Scans of weapons that are firing
Steve