I disagree with #5, I had a few of my coworkers check their sha1 against the DB and most of them were not in the dump. I also checked for truncated hashed, none of which were found. I have the feeling this is a subset of the full database
So I have a funny wild theory...remember back when the Gawker database was compromised? And LinkedIn forced a password reset for users who (according to what I read) used email addresses that matched the Gawker leak?
What if they also (or actually) compared password hashes from their database to the ones released in the Gawker breach? In that case, they likely wouldn't have pulled data straight from the database but actually might have pulled passes from the db, output to text files, cut the text files up to parcel out for processing via Hadoop or something? And somehow one of those text files got loose somehow...or someone MiTMed the actual process (I'd vote for a floating text file just because it's been so long; the Gawker breach was in December 2010).
my fairly complex alphanumeric+symbol password IS in the dump, though not prepended truncated with 0's and the other one I found, which my coworker admitted was too short and alpha only, was in the dump with prepended 0's.
This could validate the fact that the truncated hashes are actually already cracked.
My password is in the dump. I use the Forget Passwords Chrome extension , which is based on pwdhash.com, and generate site-specific passwords based on a master password -- i.e. my password is only used on LinkedIn and it's unlikely that I share it with someone else.
I think I have changed to this password during the last year.