All very true. And, another hint if you are in the job market or going through litigation: watch what your friends and your "friends" put on your facebook page (or theirs, if they identify you by name). If it's you and it's "bad," it won't matter whether you posted it or someone else did. Search engines turn up all that stuff.
Like Agent G, I've found self-incriminating web posts and pictures, and on a couple of occasions, I've interviewed a subject who denied doing something ~ ~ ~ only to brag on twitter the next day about how he/she outfoxed the stupid investigator! D'oh! Fail!!