Many apartment buildings bundle internet service with rent, putting everyone in the building on a single, easily accessible network. Sometimes they’re open networks anyone can join, with a portal you have to sign in through to get internet access. Other times they use a standard WPA2 password, like a typical home network. Some apartments may go as far as to create separate Wi-Fi networks for each apartment—definitely the preferred route—but since you don’t get to set them up, they could have easy-to-guess passwords or other security holes. In other words, if you don’t have control over the Wi-Fi network you use at home, you could be at risk.