I saw it happen with Amica, it was bought by Ontario Teacher's Pension Fund and it pretty much doubled after the annoucement.  

Is it so hard to believe that there can be people who may be privvy to insider information, but who conduct themselves in an ethical manner?  We have built in demand for over 100K shares, about two or three days volume....if things were really looking bleak I'd expect the short number to be at least 10x higher, if not 20x or more.