Is your "garbage meda blacklist" only a metaphor or do you actually have one. if that's the case, how do you maintain it and how do let it affect your browsing

Is your "garbage meda blacklist" only a metaphor or do you actually have one. if that's the case, how do you maintain it and how do let it affect your browsing (e.g. do you block the site or simply have a document somewhere sitting on your computer containing the list)?