After several months of managing our network at the student hostel, I have come to the conclusion that being a network administrator is not always nice. Users won't notice if everything works as it should. But if something goes wrong, they will start to complain and constantly demand that you fix things, whether you have spare time or not. Luckily, I'm not planning to become a professional network administrator.
When looking for free (as in speech) blogging software, it seems that they have all some kind of unsophisticated user management (i.e. they don't support Radius authentication). Other than that, there are only fully flegged CMSs, which support authentication via PAMs. However, I did not dare to install one yet.
So I have tried to insert a photo into my profile here, but unfortunately the Edit Profile form won't accept data: URIs. I think I'll have to ask in the forum what to do now. After all, not all browsers do support data: URIs.