This year, it may not just be Santa Claus who sees your kids when they're sleeping and knows when they're awake: one of the hottest trends this season is so-called "smart toys", which use the Internet to hold artificially intelligent conversations with kids while they play. Last year's Hello Barbie, one of the first to use this technology, was found to have a number of major security flaws -- including automatically connecting the mobile device to which it was tethered to any Wi-Fi network with "Barbie" in its name. Now two more toys, a doll called My Friend Cayla and the i-Que Intelligent Robot, have been found to collect data in ways that are far more worrying.