While I'm being extreme, in practical application it would be a simple reduced weighting of negative correlation users. e.g. if five people I correlate heavily

While I'm being extreme, in practical application it would be a simple reduced weighting of negative correlation users. e.g. if five people I correlate heavily with liked a /r/programming entry, that will rise above a post liked by one hundred people I have a poor correlation with. Rinse/repeat. Heavy math/statistical analysis that can be tuned to create a productive enjoyable experience, with the side benefit that it reduces gaming and exploitation.