...
- add new system setting called "SPAM protection mode" with:
- Use Captcha
- Limit Reviews/Rating Rate (see settings below)
- when the "Use Captcha" is selected, then Captcha control is added to review/rating form and unless correct Captcha code is entered nothing is submitted
- when "Limit Reviews/Rating Rate (see settings below)" is selected do what we do currently
P.S.
Maybe this should be used for Guests (not logged-in users) only.