Sounds very similiar to the surveilance plane episode a few years back with China.
Wonder what the "real" issue was there.
There was a book a few years ago that made the case that the Pueblo was deliberately put in an enticing position and allowed to be captured in order to permit the capture of certain American code equipment. The Russians and their proxies felt they had a bonanza in the captured equipment but did not have the capabilities to reverse engineer it so they just used it and copied it to use throughout their empire. It should have given them breakproof coding abilities except that the equipment had a flaw addded in that permitted our side to read all the traffic encoded with that gear. It is a fact that equipment was NOT destroyed prior to capture as the ops on that ship were intensely trained to do. I did that work in the AF on RC135s and I know what the training and directives were and it was an easy thing to do. Apparently the Red radio traffic that went through this equipment was, indeed read by our NSA for some years after the Pueblo incident. I cannot remember the name of the book or the author and cannot find it online.
The Blues Image song Mystery Ship was about that incident and I always wondered if one of those boys was on the Pueblo or another such ship or A/C. I still play that song when I get nostalgic .