I too am having to do recaptchas over and over again, even when correct.
Think about the things they are using in these captchas, cars, roads, street signs, shop fronts and block of flats.
They are just in need of human workers to help create algorithms for their streetmap / driverless car A.I.
They just pushed it a little to far this time, thats all. I am sure it will return to "normal" difficulty soon
Little bit far fetched but who knows if this is the reason for the difficulty. Maybe google is just to lazy to sort out some bugs and this keeps happening once in a while... some programs might not work 100% when used together etc... i did not have this problem for months.
Suddenly it became more difficult and got back to normal in about 2 weeks. Worked fine for a few weeks and BAM here we go again.
The bad thing is im using some ptc sites that use those captchas to solve for every click. I just refuse to solve 30 captcha's and lose 1 hour to earn a few 100 satoshi's.