It is not uncommon for some users to see extensions installed without their knowledge on their Chrome browsers. In an official blog post though, Peter Ludwig, Product Manager at Google, acknowledges that users ought to know what extension they have enabled on their browser, since extensions at times can influence Chrome‘s functionality and performance. Interestingly, according to Ludwig, it had been possible thus far to silently install extensions into Chrome on Windows using the Windows registry mechanism for extension deployment. While the feature had originally been in place to let users add a useful extension to Chrome together with the installation of an application, it was abused by third parties. It has been revealed that third parties silently installed extensions into Chrome without a user’s consent.
Chrome extension installs
Now though, two new features in Chrome 25 will allow users to run only those extensions that they want. As per latest changes, the extensions installed by third party programs with external extension deployment options will be set to disabled by default. This way, when a third party program installs an extension to Chrome, the Chrome menu will be badged, allowing users to click through the Chrome menu to see a dialog box with an option to allow the extension or remove it. Moreover, all the previously installed extensions will be automatically disabled. Chrome will now show a one-time prompt message to allow users to re-enable any of the extensions.
Earlier this year, there were reports about Google adding support for advertisements within extensions for the Chrome browser. This, of course, did not mean that Google would be adding ads to the browser, but an extension, for example, could choose to place ads within it. There are some rules that have been set in place to make sure that the feature isn’t exploited by the developers of extensions. For instance, the user was required to be informed that ads were being placed within the extension and that the ad did not tamper with the functionality of the site being viewed. Further, the developer could not force the user to click the ad or submit personal information to it in order to access the extension.
At the time, the move to implement ads was perceived as one likely to create some uproar, but with the rules and regulations in place, Google could minimise rogue extensions that tried to exploit the feature. It also opened up revenue possibilities for extension developers. Extensions on browsers have been free, so there’s close to no income that the developers receive. This recent move might change that.[source : Tech2]