(Another Tor browser user here.) Yes, it sure seems so. Half the time I visit Hacker News (which is behind Cloudflare) I have to fill in a captcha. I'm logged in with a 3k rep account and I'm not trying to do any action, I'm just trying to see the front page. That is surely suspicious enough to give me a captcha every ten minutes.
Edit: to respond to both comments at once: alright Cloudflare may not recognize my HN cookie and account, but they do have two cf_* cookies, and I am merely loading the homepage. No weird URL parameters, no POST data, nothing.
Edit: to respond to both comments at once: alright Cloudflare may not recognize my HN cookie and account, but they do have two cf_* cookies, and I am merely loading the homepage. No weird URL parameters, no POST data, nothing.