Guess what: there never was such a way, in real life, either.
Your friends may hang out at the same bar as your colleagues. Your colleagues' children may be in the same school class as your kids. Your "reckless friend" may start telling stories about you.
Controlling your reputation is hard. Keeping different segments of your life from coming into contact with each other is hard. Keeping secrets is hard.
Google and Facebook change the medium, but they don't fundamentally change the rules.