A couple of months ago, a Google engineer did an interview on this very subject where, I believe, he mentioned that text would be indexed and penalty would only be given when possible. This was interesting because obvious white text on white background would be penalized but not dynamically hidden text through Javascript because they were not able to reliably determine if the practice was intended and legitimate (a carousel for example) or malicious.
If anyone is able to find that interview, I'd be extremely thankful.
If anyone is able to find that interview, I'd be extremely thankful.