I just noticed that Google is munging search result URIs. For example, if you run a search on “mozilla”, the first result is http://www.mozilla.org/. However, the URI that they link to on the search results page is:
I suspect that the usg parameter is probably one used to prevent bots from gaming whatever results they’re trying to garner, and possibly also to link clicked search results to a specific user or browser session. I understand why they do this, but the downside for the end user is that the copy link option in the context menu of any browser is no longer useful. One needs to actually follow the link to get the URL in a form that you can copy into another application.
From my perspective, this is a pretty major usability bug, and I hope they revert it.