The Google Adwords Keyword Tool appears to have been broken. For several broad and popular searches, there are zero searches. Could this be an indication that Google does not want us to use the tool for SEO Purposes, as several broad keywords like "stop snoring" are showing 0 searches. Both the global, as well as local search volumes, are zero.

Although only a few random keywords are actually showing zero search volume, several popular keywords like iphone, ipad, facebook, etc have high search volumes. From the data, we could not find any single pattern.  There is no change seen even if the search location is changed.

Though the search volumes are not considered to be absolute they, however, give a fair idea and for several marketers [both SEO and PPC] this is one of the most important tool for keyword research. It is surprising that so far nobody has reported it, and we have seen this issue from 26th Of November, 2011.