Okay, so I have roommates and I am curious if they are able to look at what I am looking at through the router.
For instance say I am watching a video on Youtube that is contrary to their beliefs, can they use the router that they have full access to in order to spy on my internet traffic?
Specifically its a Sonic Wall router, rather high end as the people in question work for two different banks, and want to guard their network rather extensively. Do routers, high end or not have the ability to spy on those plugged into its traffic?
It is trivial with any router to see what sites you access and what URL you access. So they more than likely could see the name of the file/video you look at. Being able to actually see the content of the video stream is another matter. Since it is not encrypted it is technically possible but because many of the sites try to prevent you from copying the stream it is not a easy thing to do.
Down load a copy of wireshark and install it on your machine and capture your own traffic. You will see it is not a trivial thing to spy on people
There are multiple ways someone could "listen" to your web traffic.
* Program installed on computer (such as "Trojan" virus)
* Spyware (can forward chrome & firefox profile cache, which records history if you don't delete it)
* Hard-Drive folder sharing. (Raw access to profile data in web browser application settings)
* Router. Some routers have the option to not only log basic incoming/outgoing data, but also advanced and detailed data. For instance, my D-Link router has an option for SysLog server. Which I have configured to send to my laptop. So whenever I turn my laptop on, I have detail traffic data of every domain anyone on my router is connecting to. I can't tell the exact URL, for it's not a true Firewall, but I can see the main domain website. (I can see "google.com" in the form of an IP, but I cannot see "google.com/my_search_results").
In order for someone to know your exact whereabouts online, they must be in-between your computer, and the internet. Whether a software program does-so for them and relays that information afterwards, or if they use hardware such as a router or firewall, is the true question.
The most rare of alternatives to this man-in-the-middle rule, is when someone has a network card that supports sniffing. For instance, you cannot buy a network card from Best Buy, or Dell,etc, and sniff network traffic. These cards are not designed to receive packets in that manor. But if you are using Linux and have the means to obtain such a card... indeed, many interesting things can be seen in a simple black box with white letters. I won't digress further on that topic.