If you set "[http://loremflickr.com/320/240"](http://loremflickr.com/320/240");
as Url for an HttpImageSource you get this nice runtime exception:
(Inner Exception #0) System.NullReferenceException: Object reference not set to an instance of an object
at Fuse.Resources.HttpImageSourceImpl+BackgroundLoad.UIFailCallback () [0x00000] in <filename unknown>:0
The same exception occurs with similar URI schemes.