Sorry if I sounded like have word-salad syndrome... I knew there would be casualties but I couldn't help myself.
Think of it like you had casually mentioned to a gear head friend how cool a new mustang was that you saw and they then spent the next 5 minutes making your eyes glaze over with every detail about why the 1970 Mustang Boss 302 is sooooo much cooler.
I mentioned HUMINT because 'social engineering' is a huge part of what many 'serious' hackers do. FRAs as well I would assume. If you want to read something interesting check out the Wiki article on Kevin Mitnick. He didn't just break into the Pentagon, FBI, and IBM's system by being good with technology but he was also excellent at manipulation and subterfuge. He'd dumpster dive looking for passwords, dress up as a handyman and infiltrate a facility, whatever he needed to do to get the information he wanted so that he could exploit it later. Sometimes it's much more efficient for someone with malicious intent to just call someone at their work, misrepresent themselves as 'Bob down the hall in IT', say some word-salad jumble of technical things, and straight out ask someone for their password.
Plenty of cyber-bullying and identity theft happens in a similar fashion now. One person could create multiple facebook /myspace / gmail etc accounts, misrepresenting themselves as old friends of their target, all for the purpose of getting to know that person better to later exploit.
I'd also assume that tactics like this could be helpful in skip tracing if the person you are trying to track is computer literate and uses the internet.
Have a good weekend,
Brett
Edit: I don't know who Bill Williams is.