Yes, in fact they do. This article from AvWeb addresses the issue and includes a link to the official guidance from the FFA.

As quoted from the AvWeb article and verified by the FAA Memorandum, "Basically, the memo says camera mounts aren't major alterations since they don't appreciably change flight characteristics, performance, weight and balance or basic airworthiness. They also don't represent changes to the aircraft's basic type certification, so no STC is necessary."

http://www.avweb.com/blogs/insider/C...-222739-1.html

Bob