I have an Xfinity wireless router. I changed the admin password 6 months ago, and added parental controls to block specific keywords. Every couple of weeks, I check the parental controls history, and find that the parental control rules have triggered and the router has blocked access to websites for devices that I do not own. I have added the MAC addresses of these unknown devices to the router's block list, but keep finding new ones every few weeks. I am assuming that one of my neighbors is mooching off of my wireless connection. How can I make my connection more secure?