I write this in Blogger, and there's a helpful icon I can press to upload an image.
I run a wiki for the lab. That wiki does not have a helpful "upload an image" button. I've long seen that as a failing.
Turns out, my users found a work-around.
We use CKEditor as our interface because it would be cruel to force others to understand wiki markup, and because you can copy rows and columns from Excel and it turns them into tables.
Guess what else you can do?
You can create things in Word, copy them, and paste them into CKEditor, which saves them as data URLs.
On the good side, you can get your images onto the wiki.
On the bad side, it blows the top off the page size limits, which are put there for your protection.
I'm seriously going to have to find a solution to this, because this is seriously causing problems. But, honestly, once I got what was going on, I laughed out loud.