well i got this from seraphim:

Seraphim: yup. Steam fails.
Seraphim: I'm at the steampowered forums... it's happened to almost everyone.
Seraphim: only a tiny handful of ppl weren't affected.
[aznz] KEV!NLOL: ah you too i see
Seraphim: yup
Seraphim: I've been readding everyone since I found out.
[aznz] KEV!NLOL: mm interesting thx for the info
Seraphim: np ^_^
[aznz] KEV!NLOL: yeah because my friends were there at 6:30am this morning o.o
Seraphim: yeah, there was like a steam friends update... when ppl came back online, their lists were gone.
[aznz] KEV!NLOL: wow fail
Seraphim: Some people still had access via their community page (so their lists were broken, but they were still friends), some cannot access the community page whatsoever, but almost everyone has no friends now.
Seraphim: Yeah, check this out: One of Valve's reps posted saying "Please send us a link to your page and any relevant info"... about 5 pages worth of posts of 'here's my steam friends name and my community page' has spawned since then... in about 10-15 minutes.
Seraphim: He's gonna have a lot of work to do.
[aznz] KEV!NLOL: oh god i had like 150 friends and none were inactive
Seraphim: I had *just* cleared out my friends list, ensuring the only inactive ppl I had were just a couple of close friends from NU... I had like 150 people left after that (from 200).
Seraphim: I mean, that was only a couple days ago, too.
[aznz] KEV!NLOL: hmmm
[aznz] KEV!NLOL: so you posted a link to the forum page
Seraphim: nuh-uh... On valve's page, I mentioned in my own "here's my info", I told 'em to check out DH's community page and fix everyone in there too. Once I'm done readding everyone, I'll make a post on the forum 'bout this.