Safari on the iPhone offers users an option to enable private browsing. If you enable this setting, the browser will stop tracking your web history, your search history, as well as other user inputs such as usernames and passwords. Here’s how you enable the setting in iOS 6.0.1:

Today, I noticed that if I go to a user’s Twitter page while this setting is enabled for Safari mobile web, Twitter simply does not work. Here’s what the user sees in iOS Safari with private browsing enabled when the user goes to mobile.twitter.com/BillSimmons:

Essentially, the user sees a blank page with nothing in it. The expected result can be observed when the private browsing setting is disabled:

I really can’t think of a good reason for the Twitter mobile web experience to stop working correctly if the browser is in the private mode. Perhaps something having to do with cookies that Twitter is trying to manage on the user’s device and an error leading to nothing being shown. But either way, this is a predominantly read-only view and should be shown without issue to the user in either browser mode.