I keep a 100% wall between work and personal life for a reason. Anyone I'm doing business with I see at best as a coworker or business acquaintance, so there is no risk of merging those two realms. If you are powerful man or woman, you should be aware that people who know who you are treat you differently. This Dave McClure guy actually thought all these women were into him purely because he was some amazing dude and…
Isn't there only a risk because you're a creep? My best friends have been those that I've worked with and never once has that been a problem for me because I know how to be an appropriate human being.
No, blackmail is possible also. Obviously, you have to be worth blackmailing, but some people have some low standards for rewards.