Normally extensions and web sites aren't allowed to request information from other websites or extensions. iChrome needs to be able to do this so it can, for example, load articles from RSS feeds, or get the current weather.
Although iChrome only needs access to certain URLs (such as an RSS feed URL you enter), it can't request access to them without knowing what they are in advance. So, access to every URL has to be requested instead.
You can see exactly how all data is loaded and used by looking at iChrome’s source on Github, here: https://www.github.com/AMKohn/iChrome