I doubt they do it as aggressively as google.

While I would like to believe you the problems is that until there is a law on how much you can pester people with captchas (and you basically can pester them into oblivion) , privacy-conscious people are simply at the mercy of the sysadmin deciding for them how usable the company service is made. Which is a decidedly bad state of affairs, since he could simply wake up at any day, whip up Google-style captcha-ing and as a VPN user you simply would have no option for recourse :(