Top searches on Google.com

The following is the list of top searches on Google for the week ending April 21:

1. virginia tech
2. Cho Seung-Hui
3. boston marathon
4. 420
5. nbc news
6. columbine
7. Ismail Ax
8. alec baldwin
9. shia labeouf
10. kate middleton [source:Google Zeitgeist]