Another change you may notice this evening is that you will only see public entries when viewing another user's friends page. Your own friends page will continue to show the same content as it does today and will be the best place to read all the protected entries that are open to you. If you typically read content on the site on your own Friends' page or through a journal directly, you won't notice this change.
We will have to log everyone out again, as we did last Thursday, to make these changes this evening. We apologize for the inconvenience this causes, but is required to better protect you and your content. All of these changes should take place after 11pm PST this evening.
Please continue to watch lj_dev for a detailed technical update on these specific changes.
Edit: We are aware and resolving the issue of users with underscores in their username not able to stay logged in. We hope to have the fix live shortly.
Edit: This problem has now been resolved. We apologize for the inconvenience.