Why can't a student sign up other students for their team using the Team Signup custom course tool?
If a course using webCafé includes team signup that allows students to sign up other students, the signup database was not provided using the Team Signup custom course tool. An "open" signup of that type would also allow students to remove others from teams, to add or delete teams entirely, and to make other (possibly unauthorized or detrimental) changes. That said, some instructors build their own roster using the database feature of webCafé and trust their students to do an "open" signup. In those cases, the Team Signup tool is not used, and folders are not created automatically.
Several instructors in the past have told us they agree that it's not too much to ask to have every student sign up on her or his own. It's much more secure and prevents situations in which a student did not realize that she or he joined a team. It also helps ensure that all students taking a course are using its webCafé room. Still, if an instructor prefers a more open signup, we can provide our usual Team Signup roster format, without any automation, and open up the team entries to student editing. From that point forward the teaching team would need to enforce any rules about team size, etc., on its own.