This was contributed to the thread by contentwithcontent.
A month or two ago the google Help page on this changed. It now says:
To find a sampling of pages that link to a URL (for example, www.stanford.edu), go to the Google Advanced Search page at [google.com...] and enter the URL in question into the "Links" search box. Alternatively, you can perform a link search directly from the Google search box by typing [ link:Stanford.edu ] or [ link:www.Stanford.edu ]. There should be no space between "link:" and the URL.
To obtain a comprehensive list of sites that point to a page, perform a Google search on the URL. From the search results page, select the "Find web pages that contain the term" link, and Google will provide you with webpages that mention that address. Note that in this case, Google will return all pages that mention this URL, not just those that link to it.
If you haven't yet installed the Google Toolbar, you may want to do so. With the Toolbar, you can find sites that link to a page, search pages from a particular site, get a site's PageRank, and more. To download the Google Toolbar, please visit [toolbar.google.com...]
So Google is saying the link operator provides a "sampling" of links. It also states to search for the URL to find other links.