Is there a way to take out image from all posts?

I have site that imports instagram/twitter tweets with certain hashtags and posts these to corresponding category pages. When tweet/instagram is imported there is a script that pulls the embedded images from the post to make it the feature image (this is so the images are responsive). I need a way to now delete the image that are embedded in the post, b/c both the feature image and embedded image are showing up on the category page. Here is the page that is happening on: http://v2.insidesouthwest.com/category/lowrider

Thank you.