Arguments supporting Facebook?

[voice]

Well this probably isnt going to be a very helpfull answer but to supporting facebook here are some good thing i noticed:
-A lot of charities and organizations have facebook pages that help them raise money, get media attention and get more people involved.
-There are also quite a few facebook pages for missing children, which again, helps get more people aware.
-You could also talk about small business owners that have facebook pages which can help them get more customers through advertising and such, which can get them better business and help the economy.
-Even politicians have public facebook pages that try and get the people more involved.

You can just search on facebook for any type of (positive) organization, and cite those for your presentation.
Good Luck!