On the other hand, the phone line used for a standard dial-up connection can be tapped and data can be read directly since no encryption or access scheme is used on the link . Compared to telephone system modems, the Cable-Lynx cable modem system is significantly safer for the user.

The second myth regarding cable modem security is that if file-sharing services are activated on your PC, others will be able to see your files by looking in their "network neighborhood". This is true of older LAN based cable modem systems, such as the Zenith modems.  However, file-sharing services are in violation of our Acceptable Use Policy, and are disabled by our installers when we originally come out.  Also, having a firewall installed prevents this.  While it is possible for other people to see your files, you need to specifically set your system up to do this in advance.  The steps required to do this are several, and can only be entered by someone having physical access to your computer.  Cable-Lynx regularily scans our network for computers that have been set to allow file sharing, and notify the owner of possible security risks, and how to correct them.

Our DOCSIS cable modem system, however, is entirely Internet router based. One of the key privacy features current cable modem systems have is that IP level broadcasts are not forwarded through the network. Without this type of broadcast, no one can "see" your computer in the way described above. In this respect, cable modem services are as secure, if not, more secure than dial-up systems. This feature applies to all DOCSIS compliant modems.

To the contrary, the ADSL technology used by some Internet access providers is often "bridged" at the central office. Bridging means that others can see your broadcast packets and you may appear in their "network neighborhood" -- definitely a major security issue.