I'm on an email list with hundreds of people. It's related to a specific issue that I work with. It is occasionally used as such. Like many other lists, it is a reply-all list. Roughly once a week, the following thing happens: someone sends an email about something related to them that has nothing to do with the list; half a dozen people then reply with a short personal message to the first person, not realizing or caring that it's going to hundreds of people; another half dozen people then write "take me off this list," despite the fact that they know the account to which to send an email to get them removed; if it's a particularly meta month, people will then complain about filling up their inbox to someone from the previous three categories, and then they will argue back and forth over email that is going to HUNDREDS OF PEOPLE.So yeah, it's a problem.