When a Development Team member becomes an impediment, does Scrum Master or the whole Development Team remove him?

If the team decides, after all that is realistically being tried to solve the issue, the team member is still an impediment and the only workable solution is to remove him/her, the Scrum Master facilitates this. He is than probably going to work with HR and that kind of departments to either find a fitting spot somewhere else in the organisation or find a different challenge for that person.

Exactly what Sander said

Is it good for a Scrum Master to have "authority" over anything other than what Scrum means?

One of the stances a Scrum Master may have is that of being an agile coach. I remember Esther Derby and Diana Larsen talking about how it is sometimes necessary to "coach people off the team". That's probably the best way to look at it.

Thank you very much for your all response.

Just to confirm what I understand is correct, the story can be described as follows:

1) At first Team as self-organizing will try to solve the internal conflict with her/him by itself. 

2) After all efforts from Team are failed, (s)he is still an impediment then it is Scrum Master's responsibility to remove her/him (out of the team). Of course, depending on the context, Scrum Master can find his/her own way to help the removal process happen in a nice way.

@ Ian: I cannot find the book or blog you mentioned. Can you please check again?

I don't recall the original context or reference, but the same matter is discussed by them here: https://www.futureworksconsulting.com/perch/resources/pdfs/yourestillneeded.pdf

On one of our past projects, the XP team brought in two team members from other parts of the organization. One very bright, highly experienced programmer contributed good ideas to the team but was unwilling to entertain anyone else’s. The other individual was always “too busy” to pair or attend standup meetings, preferring to stay after hours and work alone on weekends. His desire to appear super-productive hurt the team. Often, his work was full of code smells, and other team members took on extra work to rewrite it. His predilection for overtime provided an object lesson in the value of maintaining a sustainable pace and the downside of the “hero” culture. The manager could see tension escalating as a result of these two individuals’ inability to work as team members, and sat down with them to “coach” them off the team. One left the company; the other relocated to a different department.

There are two elements to the question

1. Who can change the team

2. How can a team be changed

At Cohn's article states the team acts with a container or a system or organization which has formal and informal working practices. On of the practices will be who has the authority to change a team be that a group of people or an individual. The how is the process of that change so there is due process.

In my years of dealing with teams I get two types of individuals that create tension to remove:

1. Lazy/uncooperative

2. Disruptive

The effects of these characters is normally picked up by the SM who would look to improve performance. If it becomes difficult for improvements to be seen then organizational process kicks in due to working rights.

If you get to a position where the team wants to kick someone out then the rules of doing so need to be shared before hand.

Setting up the Team rule before hand is a good practice, then if Team can make decision to kick someone out I think Scrum Master can find a nice way to proceed the process. However, I have seen more situations like Ian described. There are reasons that can impede the Team's decision to remove someone: 

- Team members can complain about someone's behavior and don't want to work with him but still reluctant to agree on a team member separation.

- A team member is a indispensable or doing tasks well in team. Even though he is also disrupting the team's culture, team way of working, team members can accommodate with him. This becomes a tough situation for Scrum Master as managers also doesn't want to replace him due to business reason.

At the end of the day Scrum is based on two things: a functioning team and empirical delivery.

Team members don't have to like each other but they do have to respect eachother so to not work against the goal of the team (looking to display the Scrum values which are rather good). If there is behaviour that is not defined as acceptable they there must be sanctions otherwise you won't have a team. 

If you have a team member that is indispensable that doesn't want to share then you have another problem. Quite simply if the individual doesn't want to be part of the team let them operate out side of the Scrum team. It's better he's outside of the tent. You should also look to cover their skill ASAP as it's an embedded risk.

I hate to say it but it's not about being nice to everyone.