I think they are made more difficult by when Google observes "bot-like" activity coming from you. When they started the "I'm not a robot" checkbox, I used to be

I think they are made more difficult by when Google observes "bot-like" activity coming from you. When they started the "I'm not a robot" checkbox, I used to be able to just check the box and it would let me through, every time. Then, one day I had to download several dozen files, and each download had one of these checkboxes. The first 10 or so files, it let me through like it always did. Then it started giving me one CAPCHA screen for the next 10 files. Then 2 screens. Then 3, and so on. That was several years ago, and ever since then it always gives me a long series of difficult CAPCHAs every single time. I guess Google still thinks I'm a bot even after several years of solving these things pretty consistently (I'd say I have about 90% success rate). For the record, I do tag boxes containing only sign posts, or only tiny slivers of signs.