We are encouraged to be worried about the 'Dark Net' so the government can snoop on us all. In my opinion - and it is supported by History
time after time after time - that we have far more to fear from paranoid governments and brutal police forces than from any terrorists.
Those who give up freedom for security deserve neither.
Incidentally, you may be interested in who invented the 'dark net', specifically TOR (The Onion Router). It was invented by governments so they could use the internet for THEIR often very dark secrets and keep them from US, the people who employ them.