There are plenty of sites that seem to grab/crawl public profiles form Instagram, e.g. Socialblade, Instastatistics, or Likeometer.
What I read from Instagram’s TOC is that this is violating these TOCs, esp.
You must not access Instagram's private API by any other means other than the Instagram application itself. You must not crawl, scrape, or otherwise cache any content from Instagram including but not limited to user profiles and photos.
So, are all these sites operating illegally?