So spoilers, obviously.
In the season finale, we're introduced to a guy who is essentially holding the entire world ransom because he has dirt on every living person of interest filled away in his special house.
In the end, to keep him from ruining everything, Sherlock murders him in cold blood.
...just after it's been revealed that the guy doesn't actually have anything on anybody and that all of his claims are backed up by absolutely nothing.
Which means that Sherlock just murdered a guy over 'pics or it didn't happen'.
Also, you're telling me that Seal Team Six or someone wouldn't have paid this guy a visit before now? Look what we do to people like Edward Snowden or Julian Assange. Bullshit.
Also, further proof that Moffat is a poison that needs to be taken off of his vanity projects: No one in your audience believed that you killed off Moriarty to begin with. You didn't surprise any of us.