The Benefits of MLS providers watermarking MLS photos

I have been doing some research on the pros and cons of watermarking photos in the MLS.  I just called for a meeting of our New Technology Committee of the Intermountain MLS to consider implementing watermarks, so I would appreciate feedback from others as to additional pros and cons of this concept.

Pros:

1. FRAUD Abatement:  There are many complaints that people are scraping the photos for other purposes.  The most prevalent problem appears to be people taking photos of homes for sale and then creating a fictitious rental advertisement in an attempt to con people into filling out rental applications which end up being used for Identity Theft and also used to collect "deposits" on properties that aren't even for rent.  Appropriate watermarks could deter this practice.
2. COST SAVINGS:  If the watermark is the URL of your MLS's public access website, it would drive consumers to that site as the source of the information.  For example, if a consumer sees it on Zillow, Trulia or Realtor.com but realizes that it actually came from your local MLS, they could go to the source of the data and save you advertising dollars as we retrain consumers on where to look!
3. REGAIN CONTROL OF REAL ESTATE DATA:  Eventually, the consumers will realize the best source of data is the public side of your MLS.  Consumers will realize the data in the MLS is more comprehensive and more up to date than ANY other website!
4. TIME SAVING:  If this is done at the MLS automatically, each agent wouldn't need to learn how to watermark their photos prior to uploading.

Cons:

1. Watermark may detract from the quality of the image and therefore the marketing appeal of the photo;
2. Time it would take to implement the change (I think once set up is complete, it could be automatic);
3. Can you adjust (manual override) the location of the watermark?
4. Some Realtors already watermark their photos, so how do we deal with multiple watermarks?