e-mail in libraries

[earl young]

I am curious why you care what people are doing on your machines,
assuming that there is some sign-in mechanism and one use is not denying
some other use.  I know there is an argument that if the email demand
wasn't there, time would be available for others - but can't the others
also use other machines in the labs?  I don't see many distinctions
between "library" machines and "lab" machines when it comes to the
Internet.  One is that they are a way for you to attract traffic to your
library - helping build a demand to which you can point at budget time -
and I see little wrong with that.  What am I missing?  I do not mean to
come across as argumentative.  My question is genuine.  What problem
does allowing email access cause in your library?

Thank you.

Earl Young