You are incorrect. The only reason the investigation was ended was because he was told they couldn't charge a sitting president. Here is the only part of Mueller's testimony that really spells it out.
And what is this 16 fb troll bullshit? Come on man, seriously going to say that this:
Entire building was set up by Putin full of staff and computers/funds for everything they needed to do all the trolling across the internet was for 16 fb trolls? Seriously if you are a citizen of a democratic nation you need to wake up to what is going on if you are not in on it.
Do you need videos of protests set up by Russian Trolls in Texas?