Just like how someone can use a scanner to listen to phone conversations, hackers can use programs to retrieve data from you by scanning your network. It really doesn’t take much and since it’s a passive attack, you can let the program run and then sit back. It is very difficult to notice when someone is intercepting data from your network and not too many people really think about it. Hackers use programs called packet sniffers to scan your network and collect packets which they can analyze and gather data that is sent through your network. An example of a packet sniffer is Wireshark which is a free, open source packet analyzer that is used to monitor packets that are being sent through a network. While not everyone uses these programs for that reason, there still are many people that will. Though there are certainly many more programs that are much better and able to do much more which people can pay for, people can still download free programs and use them. Although it is difficult to determine what information is valuable and what information isn’t, but most hackers don’t even care, they can take what they are able to get and use it against you. It really isn’t hard for people to steal data because of these programs and it’s even worse that most people don’t find out until it’s too late that is assuming that they do find out.