Philipp Lenssen writes Planting My Search History Entries, and Social Patterns explains that this code:
<iframe src="http://www.google.com/search?q=Google+Blogoscoped+sneaked+in+through+the+backdoor" style="width:0; height: 0; border: 0; overflow: hidden” border="0></iframe>
Makes it possible for you to force someone who uses Google My Search History, to embed saved results by just visiting a page.
Currently there is no forum discussion about this loophole but there is a big discussion on My Search History and other issues at WebmasterWorld.