I agree. That was badly worded. Sorry. Unfortunately, by now I can't edit the comment any more. However, there is no technical reason why the old system would

I agree. That was badly worded. Sorry. Unfortunately, by now I can't edit the comment any more. However, there is no technical reason why the old system would not have had exactly the same means for tracking the user as the current system has. If you consider that Google is mainly an advertising company and that Google's investment into reCAPTCHA must provide them with some value, that lead me to conclude that the old system was doing exactly the same tracking as the new system is doing now. The advantage is that now I don't have to type in letters while the tracking stays the same.