Recently, it has been revealed that Pinterest reverse-image searches Google for uploaded images and adds the Google query result to the Pinterest image page for SEO: https://www.rankscience.com/blog/pinterest-image-seo-growth-...
This degrades quality of Google image search, for example this Reddit post on removing Pinterest got 77k upvotes:
Reddit r/LifeProTips to remove Pinterest from Google searches: https://www.reddit.com/r/LifeProTips/comments/hejbl0/lpt_whe...
Earlier Reddit petition to Google to remove Pinterest from search results (66k upvotes): https://www.reddit.com/r/google/comments/85atho/pinterest_ne...
Hacker News discussion of Pinterest's Google scraping: https://news.ycombinator.com/item?id=23701998
Earlier discussion on HackerNews (1.1k upvotes): https://news.ycombinator.com/item?id=16613996
"Unpinterested" Chrome extension to combat Pinterest spam (10k+ downloads): https://chrome.google.com/webstore/detail/unpinterested/gefa...