Describe your issue or idea
I want to make ALT tags on images required. There is a module I could port but I think this should probably be in core and active as a default for new image fields. Side note: I also see that D8 has this in core:

From that D8 issue:
Alternative attribute text is required for images to ensure a site meets WCAG accessibility guidelines. When adding an image field to a content type, the alt text field is currently optional meaning Drupal sites often fail accessibility audits until alt text is added to images.
Note: This issue does not relate to images added via CKeditor. It relates to changing the default setting on the image field to require the alt attribute.
Recent comments
OMG thank u... you are amazing.
Hiding Blocks for Small Screens
I use a similar module (Tocbot) which uses the same library, but the implementation is different. This is what I use to target the block: @media (max-width: 47.99em) { .js-toc-block.is-...
Hiding Blocks for Small Screens
So the implication is that another module is causing the trouble. Now for the slow process of elimination... Sounds plausible. And good luck with digging...
How to troubleshoot interactive image cropping modules?