I don't know what this number goes to, but with my pre-paid credit card, I attempted to set up to receive cell phone alerts of my transactions and this number was already on the website as receiving texts as to when my account was used, which the texts include balance information and where the transactions were located.  Watch your pre-paid cards and check the websites for the automatic alerts sections - someone may be able to find out how much money you have and where you are using it...if they can access that on the website, who knows what other information they have gathered!!!!!