If you leave your bike locked up outside the university, when you head home after work you will find your bike covered in fliers. That is if you are lucky enough to find your bike at all.
On the plus side, the spam I have been getting to my theorem account has been way down recently. My understanding is that spam is so bad now that we cannot deliver all email anymore. Now email is filtered even before I get it, and so sending email is now fundamentally unreliable. Or maybe there is some other reason.