Hater is the brainchild of ex-Soundgarden bassist Ben Shepherd, and is a combination of members from Soundgarden and Shepherd's previous band, Episode, plus John Paul McBain of Monster Magnet. The lineup consists of:

Ben Shepherd: guitar, foot-perated Theremin, vocals
Matt Cameron: drums, guitar, bass, backup vocals
John Paul McBain: guitars
Alan Davis: bass

FORMER MEMBERS: Bill Rieflin: drums (never a full-time member- only played a couple of studio tracks)
Brian Wood: vocals (left after first album- also, the younger brother of the late, great Andy Wood, singer of Mother Love Bone)
John Waterman: bass (left after first album)

Not to beat a dead horse to death, but this is yet another great example of the incestuous nature of the west-coast rock scene, even ten years after the peak and death of "grunge."

Shepherd started with a little band called March of Crimes, then founded Episode, moved to Mind Circus and sang for Tic Dolly Row, then picked up the bass and played for Soundgarden before founding Hater, Devilhead, and the incredible Wellwater Conspiracy, each of which he sings and plays various instruments for.

Cameron began with Feedback, which later became Skin Yard, then moved to Soundgarden and was involved with the subsequent Temple of the Dog project, then co-founded Hater and Wellwater Conspiracy. He also recorded with the Tone Dogs, a Seattle-based jazz group, and recorded with the Buddy Rich tribute band. Now he plays for Pearl Jam. Oh yeah, and by the way, he sang the song "Puberty Love" on the Attack of the Killer Tomatoes soundtrack.

John Paul McBain started out with Monster Magnet, and has been sticking fairly close to Ben Shepherd since, participating in Hater, Wellwater, and Devilhead.

Alan Davis has played as a studio musician with several singer-songwriters, most notably the incredible Mark Lanegan.

Bill Rieflin played for a long time with Ministry, and also stinted with Nine Inch Nails, KMFDM, and R.E.M. before teaming up with Shepherd in the studio for some music fun-time.

Hater has released two albums, as follows:

1993- Hater -A&M Records
2005- The 2nd -Burn Burn Burn Records
SOURCES:
http://www.billboard.com/bb/daily/article_display.jsp?vnu_content_id=1000808709
http://cycletheory.tripod.com/members.html
http://www.downundershoe.com/orig/band.html
http://www.drummerworld.com/drummers/Matt_Cameron.html
http://www.dailytrojan.com/main.cfm?include=detail&storyid=942554