Your comments

I understand that, Matthew. I think that the "group" concept is wide enough to comprehend the "account" and "individual" backlog rights. It is simple enough to create an "one-man group" and it is also simple to create an "everyone's group".

I just had this very same problem on one application I developed and this approach saved me a lot of time and also the users were happy with that.
This is a really interesting thing. Maybe, if we rename "company" to "group" and allow multiple groups to be associated with a backlog...

This way you can associate users to groups (aka. company) and have predefined sets of users that can participate on a backlog.

A group could be a company such as "Google", "Yahoo" or a group of users that share the same role "Supervisors", "Admin", etc.
I thought it was really intentional as easybacklog doesn't have an online task board. However, my main challenge right now is: How can I use scrum while working with a team scattered around the world? Is that even possible?

In the last year I found that people get motivated if they have a easy way to know that their partners are also working hard on the project. It is impossible for us to have a daily scrum meeting, and this is the best way we can get to know about what is happening on other parts of the project. This request is somehow connected to the "Activities tab", but I preferred to suggest them as separate topics.
I think single updates would be better. Although it might generate some overflow, it is important to know what is happening. Also, if you detect a new kind of activity that should also appear in the feed (comments, sprint review, sprint results, etc) it would be easier to implement that.

The feeds should be unique per backlog, so people can follow only the feeds they're currently working.
Yes, kinda like that. In fact, that would be more useful if the other idea about Comment threads on User Stories were also implemented. The "Activities" could also have a RSS feed (here, at the top right corner, UserEcho does this), so people on project could follow the project from google reader, other RSS readers, and mainly mobile devices (that would be a huge benefit providing that every mobile OS has a RSS reader and you wouldn't need to develop easyBackLog for Android, iOS, BlackBerry, Symbian, etc).

I know exactly why you won't implement the "comment threads" for now and I agree: you must focus on the core business of your product. And I agree. Perhaps this idea should also be "freezed" for now, but keep that in mind for future releases.