Most companies like enthusiastic customers, so long as they aren't too enthusiastic. Marketers like customers who respond to campaigns, but they get very nervous when customers take control of the brand on their own initiative. It sometimes ends up taking the brand in a direction the owner would prefer it didn't go. (eg. Cristal, Burberry)

In this case, you've got multiple people sharing what should be an individual account and the potential for damaging mainstream media stories if people feel like they're doing a good turn for strangers, only to have scammers empty the card. Not to mention that if Jonathan's Card is genuinely unconnected to Starbucks, his use of their trademarks would make the lawyers uncomfortable.

This may not be a full-fledged viral marketing campaign, but I'm skeptical that Starbucks would be so enthusiastic about it if the guy responsible didn't have a preexisting relationship with their marketing department.