The thought of people using modems has not crossed the designer's mind. Unfortunately, many designers test-drive their web sites using their internal nets. A proper check using a modem should always be done before a web site is put up. For instance, every time you try to look at particular web site, your computer crashes or the screen freezes. Accessibility for all is a crucial issue.
Some web sites like to use moving pictures.
People literally can get motion sickness from these sites and this may make them nauseous. They also take forever to download with a modem. Often computers that are older will not support these flashing moving pictures. Streaming Video Clips require tremendous memory resources that many older computers just do not have. This is due to poorly written code usually javascript or java.