Robots will not pass!

Every day the number of sites and services on the World Wide Web is growing. There are more and more new services that want to meet the needs of people. Most services require registration. And here the developers have a question: how to prevent or at least reduce the number of registrations carried out by robots. The system of protection from robots de facto was the recognition of distorted letters and numbers. These same characters are distorted in the hope that the robot will not be able to recognize them and continue registration. From my own experience, I can say that even a person sometimes has to wrestle in an attempt to solve the mysterious combination of characters. There are other ways to prove that you are a reasonable person: solving elementary arithmetic problems, answering a banal question, etc. ways to show logic and sanity.

There are few exceptions. Only once I was asked to enter my phone number, which the robot subsequently called and gave me a key number, by entering which I was able to complete the registration in a specially designed form. Yesterday I learned about a new method on one of the sites. Its essence is the following: you are offered a certain number of photos of girls, from which you must choose simpotichnyh (a certain number), after which the registration will be completed successfully. I myself have not seen sites using a similar technique, but I wonder how much these girls differ in their appearance, where photographs come from (I don’t think that girls collected and photographed for this purpose), and how much traffic is spent on this process.

Having written all this, I remembered the technology OpenID. It is interesting to hear your opinion about this technology.