Flickr made a big announcement that the countdown to the single sign-on has started: in other words, away with your 'old skool' Flickr login and welcome to the world of Yahoo! integrated logins. This has produced a very active thread in the Flickr forums. It's funny to see actions of near-surprise, given that this was foreshadowed when Flickr was originally bought by Yahoo. But more than the feigned shock, this has been interesting study for me as to why some people are reacting so negatively. It takes me back to an older entry where I discuss my own personal theory on megaservices attempting to do public community sites:
... my Google and my Yahoo identities are too personal to give away in a community service. Google/Yahoo identities are tied to e-mail, search history, calendars, and more. If you publicly reveal that identity you at least open yourself up to more spam and at worst invite identity theft of a much larger scale: determined individuals can figure out who I am from my Flickr account, but that's because I chose to tie my Flickr account to my overall 'kwc' moniker. It's related to danah boyd's mention of managing social contexts, e.g. teens don't necessarily want to hang out in the same social space as their parents (related: MySpace is drawing older visitors, study finds).
There is also a technological corollaries to this. My "home page" for Google is private-facing while my "home page" for Flickr is public facing. A company managing your private identity has to have less lax login procedures: Flickr can keep you signed in for weeks, Yahoo needs to sign you out almost immediately. There is also screen-handle assignment: I can be 'kwc' on Flickr, due to the smaller user population, but there is no way I would ever be able to get that for Yahoo.
So, what is the point of all this pontificating? To go back to the original question, I do think big companies storing your private data can successfully create new public community services, but they have to create separated sandboxes for these services. They have to allow 'alter egos', perhaps many, so that you can remain in control of your privacy. This is what they effectively do when these large companies acquire community services, but sometimes attempt ruin the whole deal, e.g. Yahoo's announcing they will merge Flickr accounts with Yahoo! accounts. Arguably, this is what Google did with Orkut, but Orkut couldn't scale to meet demand.
I thought there was a tad bit of wisdom there -- after all, Google's Picasa Web albums now allows you to create an alterego URL for sharing your photos. But I think I was wrong, at least in the case of anything to do with Yahoo. Reading through the thread, it basically boils down to: Yahoo... isn't... cool.
That's a bit of an oversimplification, but a lot of it boils down to the fact that Yahoo is a bad brand and some Flickrati don't want to be associated with it. Flickr, after all, is a high mark of Web 2.0 brand coolness: Apple may own the vowel 'i', but Flickr has caused countless sites to disown 'e'. But this changes everything. You now have Thomas Hawk of Zooomr (a Flickr clone in both design and vowel omission) not-so-subtly trying to poach Flickr members in Flickr's own forums.
The fact is, Flickr did just about everything right*, but the bad brand experience of Yahoo outweighs this. In other words, Yahoo has done plenty to make its brand a pariah. Many in the Flickr forums think a Yahoo ID means that they have to re-login everytime they open their browser. Many also think that their Flickr accounts are going to be deleted for inactivity the same way other Yahoo properties do. But there's actually no difference with this transition: the Flickr team changed nothing other than requiring a Yahoo login ID. You can even use one Yahoo account to login to Flickr and then login with a different Yahoo ID, all the while staying logged into the Flickr (for those worried about their Flickr identity being tied to their more private data). But still, the Y! merger makes Yahoo's bad brand experience transitive.
This isn't to say that if you were to substitute Google for Yahoo you wouldn't have the typical "X is evil" comments, but there are least several comments in the thread that indicate that this only matters to them because Yahoo sucks in comparison to Google. I feel a bit sorry for Yahoo. They acquire many companies I like (Flickr, del.icio.us, MyBlogLog), they release cool projects like the Creative Commons Search, and they have interesting bloggers like Jeremy Zawodny, Tom Coates, and (briefly) Simon Willison. But then you read scathing articles in Wired on their CEO and you feel sorry for the individuals that do good work at a company that doesn't have it all together.
Anyway, my take on this was to extend my Flickr Pro membership 2 more years. It was actually due to expire when the switch was going to be thrown, but I've liked the acquisition by Yahoo. I doubt that unlimited uploads would have occurred if Flickr was still a small company. I also suspect that there would have been a lot more "Flickr is having a massage" messages. Unlike many other sites, Flickr provides a public API so that I can walk away with my data whenever I please.
* Flickr did also announce a 3000 contact limit at 75 tag limit, all in the name of performance. The contact limit only affects 300/6,000,000 of their user base, but arbitrary limits always come off as... arbitrary.