[the first result for "spammers" in a Google image search]
The mail services required very little information to sign up – basic biographical and geographical information was acceptable to register for an account – and the necessary information was unverifable.  Spammers developed (extremely simple) computer programs that could fill in that information to create thousands of fake email addresses over an extremely short period of time and then use those accounts to deliver massive amounts of UBE indiscriminately. For Yahoo!, this corrupted their users experience. They were rogues, criminals, infecting your safe space with what didn't belong. This couldn't work without the ideological manufacture of how you see and what you feel in front of your inbox.