today, i want to introduce to you an often requested extension: Image Hotlink Control
This extension allows you to control embedding of images respectively limit and/or allow/disallow embedding under certain circumstances.
Enabling the whitelist mode (see screenshot) prevents posting of images from hosts, which are not listed in the subsequent list. When disabling the whitelist mode, embedding of images from the listed hosts will be denied. By adding |includeSubDomains next to the host name, embedding of images will be denied/allowed for all subdomains of the given hostname, too. Adding |allowHTTPS allows embedding of images from the given host when using HTTPs.
The option Remove protocol for local images removes the protocol from local images (via //), so images are loaded depending on the current protocol that is used to visit the community, regardless of which protocol was used to embed the image.
The option Allow embedding of images via data URI should be self explanatory. More informations regarding data URI can be found here: Data URI scheme - Wikipedia, the free encyclopedia
Another option (which cannot be found on the screenshot) is Allow embedding of images via file URI. Images, which are embedded from the local computer cannot be viewed by anyone except the person, which embedded it. It seems, that some people don't know this, so this option will prevent it. More information regarding file URI can be found here: file URI scheme - Wikipedia, the free encyclopedia
Last but not least, there's the option Use ImageProxy. As you might think, it's the ImageProxy by Josh which has been completely integrated into this extension. When enabled, exceptions won't be thrown in "normal cases". Instead, affected images (not all, just those which are not allowed to be embedded according to your whitelist/blacklist preferences) will be saved locally and served from the own host, using the image proxy.
For a future version of this extension, it's planned to add a protocol to the ACP, where you can exactly follow the embedding of images. But there's no ETA, when this function will be available.