Love the series. My problem with this episode. British intelligence had Moriarty in interrogation about the code. Sherlock bought into the code. In the end there was no code, just underlings doing daylight robbery.
I just can't buy into that the Brits don't have their own NSA, people who would be able to tell in minutes that there was no code, that these breakins were done by someone sitting at a specific computer, and they would be able to pinpoint that computer in no time at all. As Moriarty said, did Sherlock really think he could bring around world collapse with a few lines of computer code?
The entire premise falls apart after that reveal. That this Sherlock would fall for it is no Sherlock I've ever known. That we're to buy that and also buy that the source of those keystrokes could not be identified by experts, that they wouldn't be able to determine there was no code delivered or in the system, is asking too much.