Most people want to believe their brand is as special as Coke or Apple, but they usually aren't. Most people will not know what a Verisign logo on a web site means in terms of actual security measures, they'll only see it as a label saying "hey we claim to be secure!" And those who are familiar with Verisign will associate the logo with their misdeeds, and wonder why they should do business with a site that does business with such a company.