Thats because under the covers, the user script is actually converted into an extension.

This means that management tasks like disabling and uninstalling work just like they do with extensions.Boodman notes that scripts have full access to private data on sites, so you would want to be careful about what you install, and use caution when trusting them. Not all of the scripts work with Chrome yet Boodman estimates 15 25.According to data from NetMarketShare, Chrome made market share gains in January, taking share away from both IE and Firefox. The browser gained .6 for the month.