Here is how I permanently stopped my galaxy note 4 from creating thumbnails. As you may not know, those thumbnails occupy a sizeable chunk of space on the phone's internal memory. For me it grew to nearly 600megs and for other people it will be far larger especially if you have lots of photos.
The first step is to open a file explorer capable of showing hidden files and folders, that is those with a period in front of the name. I used Root Explorer since my phone is rooted. I don't think you need to root your phone to have success with this method.
Step 1: Go to the Camera Folder.
Step 2: Delete the .thumbnails Folder!
Once deleted make a new file and name it:
Step 3: The Prevention!
I hope this has been helpful to you folks!
Step 4: Known Issue!
Therefore if you have any app that needs to upload pics, like instructables or Facebook then you gotta allow thumbnails permanently or do my workaround.