A screen shot of the trademark page, and directions on how to get to that trademark page are posted below:
1st: click the link, --> http://www.uspto.gov/ebc/indexebc.html
2nd: You will see three columns: Patents, Trademarks, other. Click search(TESS) under the Trademarks column and Trademark EBusiness
3rd: Click 'New User Form Search (basic)'
4th: Fill in 'Blizzard,' for the 'Search Term.'
Note: Be sure to assign 'Owner name and address' for the 'Field' parameter!!
5th: Look for 'Diablo.' It should be the first one (There is one for Diablo I, II, and one for LOD, but LOD says LOD, LOL).