Stephanie Tilenius, vice president, e-commerce, Google

The announcement that Tilenius was joining Google came a matter of minutes after CEO Eric Schmidt’s keynote presentation at this year’s Mobile World Congress in Barcelona. And as one operator executive pointed out, hiring the woman who created PayPal for eBay was probably not done “so that Google can interface more successfully with operator billing systems.”

Google plans in the future to have access to a greater level of data about end users than operators currently enjoy and the firm represents a significant threat to the established order of the mobile carriers. Over the top billing is already one of the biggest problems facing mobile operators and Tilenius’ work at Google isn’t likely to do anything other than exacerbate this.

Like her colleague Susan Wojcicki (who appears later on the list) Tilenius has worked at Intel. She has also spent time at AOL, FireFly and Alex Brown.