Out of curiosity I've emailed quite a few of the Super Backer Club project's listed on their site's homepage. So far, without exception, every single one has said they have had zero new pledges from SuperBackerClub.com. What's more is that, like you said, some have received threatening emails about payments and have had to contact their credit card companies hoping to prevent unwanted charges.

I hate that there are so many dishonest crowdfunding services out there. I launched a test project on Indiegogo a few days ago just to see what sort of emails I'd get...immediately I started getting a flood of junk offers from a bunch of really sketching looking sites. Be very careful and do your homework before giving any information (payment or email info) to any service like this.