Google for "The Mystery of When to Stop Antidepressants" and click through there. Didn't work for me in 'incognito mode' but it did when running normally. YMMV.
There seems to be sites that think of private browsing as ad blocker. A watchdog script and firefox with new profile takes 10 seconds ... why do they even bother.
I was totally unable to bypass it as well.
Same here. Tried Chrome and FF in regular mode, all extensions off.