I don’t think it harms the publishers. If the ad network (well, Google) does detect it, I think they just won’t pay for the “fraudulent”¹ clicks? (And in best case scenario, you’re actually helping small sites!)

Advertisers on the other hand will pay for nothing, yes. Some of them are small businesses. I wonder if there’s a way to click on big corp ads only...

Edit: ¹ – added scare quotes, see https://github.com/dhowe/AdNauseam/wiki/FAQ#how-does-adnause...