Twenty-five year ago that would fool people. Now things are complex enough that you can't help but leave clues even as you're trying to plant them.

The DPR was caught in part from a post on Stack Overflow where he was asking a question unique to his platform. Imagine how hard it would be to write the Flame malware. Now imagine the NSA and CIA hunting for traces afterword. Building that malware required deep information on many system that would likely require badges or intensive social engineering to access, both of which leave traces. Do you really think you could hide?

I'm an expert (of sorts) and I'm not sure that I could buy drugs on the dark web 100% securely if those resources were hunting me.