For some reason all query strings are being html encoded ( in hrefs and src attributes)

example

/WebResource.axd?d=N54G7Jy7_SEfEVVk2tD43A2&t=633833943844060961
should be
/WebResource.axd?d=N54G7Jy7_SEfEVVk2tD43A2&t=633833943844060961

Anyone have an idea why this is?