Great writeup on the Silk Road investigation by Wired magazine. Silk Road was the most high-profile deep-web ebay clone for illicit drugs and paraphernalia, before it was seized by the FBI late last year.
The TLDR summary: real-life cybercrime investigations is nothing like you see on CSI:Cyber. It's long tireless hours of surveillance, interrogations, complicated dealings between jurisdictions, and generally good old-fashioned police work.
The reason is because in real life, lengthy passwords, VPN, RSA cryptography, and all these technologies are actually pretty damn secure, which gives law enforcement quite a hard time. It's humans that are fallible: we put untested code on live servers; we connect to our super-secure websites from Starbucks; we put incriminating notes and photos on Facebook; we even write detailed ledgers on paper.
So that scene where a Agent Bow Wow types really fast for 10-minutes plus commercial break, complains about encrypted firewall layers, then guesses a 12-letter password on the first try based on Arabic nursery rhymes? That's not real life.