Years ago when Amazon had unlimited photo storage, you could “hide” gigabytes of data behind a 1px gif (literally concatenation together) so that it wouldn’t count against your quota.
They still do if you pay for Prime. I was surprised to see that even RAW files (which are uncompressed and quite large) were uploaded and stored with no issues. Not the same as "hiding" data but might still be possible.
In the interest of technical correctness, RAW files are frequently compressed and even lossily compressed. For example, Sony's RAW compression was only lossy until very recent cameras.
Given that there are the options for uncompressed, lossy compressed and lossless compressed, I'd say RAW files differ in the stage of the data processing where capture is being done and doesn't imply anything about the type of compression.
What is relevant is that the formats vary widely between manufacturers, camera lines and individual cameras, so unlike JPEG, it's really hard to create a storage service that compresses RAW files further after uploading in a meaningful way. So anything they do needs to losslessly compress the file.
Interesting, so are you saying that the RAW signal coming from the hardware is already often compressed even before hitting the main software compression?
Oh, no. What I'm saying is that cameras often take the raw signal from the hardware, but then the camera software frequently compresses that signal before writing it to a raw file (.cr2, .arw, .dng, whatever). This compression can be lossy or lossless. It's important not to confuse the raw signal with the RAW file (an actual format, often specific to the camera manufacturer). Just by saying RAW file, assuming it's lossless or uncompressed is false. So it should be specified - uncompressed RAW (lossless almost by definition), lossy compressed, lossless compressed.
