Most of websites put some restrictions on how to use their services; the following paragraphs are taken from “Terms of Service” of such website:
Only one account per computer is allowed to view ads. If more than one account in a single computer view ads, all of those accounts will be permanently suspended.
User can only use a maximum of 3 distinct computers in a 10 days period to view ads. Any attempt to use more than that in that defined period will cause an account suspension.
Question:
No problem with such rules, they must be respected. But I want to know how can servers recognize a specific computer! Is there a computer fingerprint that would be transferred through HTTP connection and can identify each computer?