This is to remind everyone that even though it is easy to change Orkut codes using Greasemonkey scripts, it can lead to undesired actions which are carried without your consent.
Theme's and scraps have scripts embedded in them which commands joining certain communities. Sometimes you may not be able to easily unjoin the communities because of error messages. Try logging out and logging in after sometime and unjoin the communities.
Be Careful! Especially if you have no programming knowledge. Don't run any scripts.
~~The End~~