‘Useless’ isn’t a strong enough word. The way it’s broken Google image search puts it way into negative a value.
Try adding -site:pinterest.com to your search query.
Edit: Just tried it myself, might want to add a -site:pinterest.co.uk as well.
Im amazed googles allowed them to pull those seo tricks so long considering they put the hammer down on ehow with the panda update.
Pinterest would be up there too. It's useless if you don't have an account on mobile and desktop.