Greenpeace as a global environmental organisation have a big online community: Greenwire.
There are 20 different Greenwire communities, one for each different part of the globe where Greenpeace has offices and operates. In each of them the users with interests in Greenpeace projects can get in touch between each other and receive informations about the organisation updates.
In each community there are several groups, with open chats, that the users can join: some of them are about a particular geographic area — for example a certain zone of London or a region/city of the country — and some about a certain interest or job that combine people — like the Social Media Activists or the Legal Support. In each of them people who want to support or be activist in Greenpeace can receive update regarding the projects that are going on in its own area or interest field.
It is possible also to read blogs and watch videos about own experiences in Greenpeace and sharing new ideas regarding the environment, Greenpeace campaigns or possible actions to raise awareness of the environmental issues.
In Greenwire it is possible to recognise all the characteristics of online communities describes from Baym: the users share the online space, practices, identities — they care about the same issues — and resources and support. They create interpersonal relationships based on same interests.
I believe Greenwire is a great example of online community, even though at the moment still have a geographical limitation. It is possible, in fact, to register just in one country at the time. I believe this could be improve, allowing people to join communities from more than one country: for example, I am an international student and I could be happy to be part of the communities in UK and in my home country.
If same of you is interested of discovering more about Greenwire, this is the UK site: https://greenwire.greenpeace.org/uk.