I have seen plenty of Capcha's around the 'net over the last few years, but this one (in the 'Qualifying question' section) is definitely the best anti-automated subscriber trap I've ever seen. The neat thing about it is that it also distinguishes between normal humans, and 'humans that are smart enough to use the site'! In this case, it's the Quantum Random Bit Generator Service from the Rudjer Boskovic Institute in Croatia.
For some reason, they think that only people with a university degree level maths education should be able to use their random number generator. An interesting criteria in the Web 2.0 world of interacting services. Mind you, they don't even have a Java API, now or in their 'Coming soon...'. Unless that's what's meant by their cryptic 'Web Service Access' line at the bottom of the list.
And what kind of serious 21st Century, third party library expects this requirement: ' You must edit the code and change logon credentials (username, password) to be able to access the Service.' Whatever happened to property files, XML config files, environment variables and command line parameters?
Come on guys, get with the program!