According to this article Ryanair stopped using captchas:
The article makes a few bald statements of how dependant ryanair is on the travelagents. Ryanairs answer to this seems to have been to move the captcha further up the booking funnel to prevent availability scraping. This is a bold move as it forces normal customers to fill out the captcha even before viewing the flight options and could have a negative impact on normal sales.
It is apparent that Ryanair are comitted to cause problems for the OLTAs that breach their terms and conditions of use and that Ryanirs view of their business is somewhat different from what travelweekly assumes.