bonus points for raising these issues before Twitter brought them to the forefront.

>political censorship pressure on the URL-shortening service

Couldn't this be mitigated simply by establishing credibility for a given service, in the sense in the sense of making it known to be hosted outside politically supressive jurisdictions or by parties resilient to political pressure? For example, I would trust a URL-shortening service hosted by The Pirate Bay or Wikileaks to be free of political censorship.

Both of those have gotten shut down in various locations at various times.

Sure, shut down...but they've never published/made available politically censored content.

and what if you live in a country that blocks that url-shortening service hosted by the pirate bay or wikileaks?

Well, then you've got bigger problems than URL shortening. I don't mean to be flippant; if you're in that kind of country then maybe you can't even trust your normal DNS.

my point (and i think that of the person you originally replied to) was that if you have to go through a url-shortening proxy to get to a page that is not blocked, but the url-shortening site is, you will be blocked from accessing a lot of content simply because you don't know its real url.

Ah, perhaps I misunderstood. I thought political censorship pressure meant the government pressuring the URL-shortening service to change the target of short URLs that people try to use to point to politically disagreeable content.

Or if your school's webfilter blocks tinypic and some of the other url shorteners. It's one of the most annoying things about trying to read tweets or reddit these days.