Google promised control of each Chrome extension’s permissions back in October, and that long-promised feature finally arrived near the end of December. Extensions no longer requireall your data on the websites you visit.”    You won’t see any sort of prompt when installing an extension. If that extension asks to “Read and change all your data on the websites you visit,” all you can do is agree and click “Add Extension.” But, after the extension is installed, you can now revoke that permission.