Every home user has a modem that lets them connect to the Internet and is usually provided by their ISP. A popular manufacturers of modems is Arris and they often look something like this:

I was looking into which of their models was most popular and trying to collect some stats on them (stay tuned for a post about that) when I noticed something strange yet familiar:

Shodan returned about 330,000 results, and nearly 2/3 of them are located in Chile. The devices are easy to find on the Internet but I had never realized that they were mostly concentrated at a single ISP. VTR Banda Ancha S.A. is deploying their modems with public web interfaces that broadcast a lot of information about their customer's network:

You can see the SSID, MAC address of the WAN and LAN interfaces and determine the firmware/ product that the customer is using. The ISP uses the Arris WTM652 (PDF) modem to provide their customer with WiFi and a bunch of other features. And the modem is known to ship with an administrative interface that doesn't require a password (source). I didn't verify that this is the case with these modems deployed by the Chilean ISP, but it wouldn't be a big surprise if the devices don't have a password set.