twitter for journalists
URL shorteners compress standard web addresses to reduce character length. Because Twitter limits the character length of tweets, shortened URLs have become a requirement in the age of microblogging. While necessary, be aware that there are potential security issues with shortened URLs. Fortunately, all of the big URL shortening providers are very aware of this potential, and do a lot of filtering and screening to keep users out of trouble. You should be aware, but not overly concerned.
There are many URL shortening services available, including Bit.ly, is.gd, the Hootsuite-owned ow.ly, goo.gl and the original TinyURL. Twitter also runs its own shortener t.co, and forces all URLs posted through services it owns to go through it (this means that if you post a bit.ly URL through an official Twitter client or twitter.com, it will be re-shortened with a t.co link!)
Some services also offer custom URL shortening with your own organization's domain, which is why you sometimes see shortened URLs like abcn.ws, and nyti.ms.
As you surf Twitter, you'll come across a wide array of shortners, both generic and custom.
Here at KDMC, we use the bitly Pro service to sometimes shorten URLs with the domain kdmc.us.
URLs can be shortened in advanced by going to a common shortening service, or may be compressed by your Twitter client as you post. Twitter.com also has a built-in URL shortener:
After pasting a URL into the twitter.com post field, a "Shorten" button will appear. Click it and the URL will be shortened with the t.co domain. You'll see the character counter reflect the change.