Due to this, Steam announced a few hours ago that they will be making changes to how Steam installs game updates to try and save the bandwidth of its users.
Steam has already been limiting automatic updates to games played within the last week, but this threshold has been brought forward, so Steam will now only automatically update games that have been played within the last three days. Games will still begin you update when started, and manual updates can still be initiated.
Users are also encouraged to manage their own updating options, such as setting specific windows for automatic updating so you can control when Steam updates your games, throttling your own download speed to ease the load on your home network, and using Steam's Library Folders settings to move infrequently-played games onto an external hard drive instead of uninstalling and later reinstalling games.
Steam offers a help page for managing Steam downloads on their support page, which contains instructions for managing bandwidth settings and automatic updating among other options.