It depends on how bad their behavior was and how much I like their work. Im thinking of examples:

Pedophilia - Polanski
Racism/inciting violence - Ted Nugent
Infidelity - Picasso
Addiction/general jerkiness - RD Jr

I dislike all the above though. I don't think I could ignore the first two indiscretions. The second two, maybe.
Originally Posted by The New Black
The key distinction is the extent of harm inflicted on an innocent victim. The first is unforgiveable, the second may not be criminal but is sufficient basis for a public sanction. The last two are pretty tame for me. If we refused to patronize anything produced by an unfaithful person, we'd never listen to another CD or attend another movie!

I find Polanski's ongoing popularity reprehensible, especially since he continually flouts his ability to evade justice.