There's also the whole lack of security in the "secure" environment to consider. From what we see in canon the protection (if it exists at all) is so full of holes as to be worthless.
My theory is the Malfoy and company found Harry long before he got to Hogwarts--and then realized that there was nothing they could do to him that was worse than what Dumbledore had already done. Perhaps they spent their weekends sitting around under magical concealment eating popcorn and watching Harry's home life...
My theory is the Malfoy and company found Harry long before he got to Hogwarts--and then realized that there was nothing they could do to him that was worse than what Dumbledore had already done. Perhaps they spent their weekends sitting around under magical concealment eating popcorn and watching Harry's home life...