I don't think they've ever been on, or rather they shouldn't have been.
There are a few things coming up so they might very well be turned on in the future, only thing that concerns me is that we have a large element of modem'ers and picture signatures could potentially really slow things up for them.
I shall certainly think on it and I don't doubt that we'll trial it in the future, I'll just need to come up with some constraints on the image size etc.
If you haven't heard anything more in a month kick me!