What is the purpose of CERN?

What is the possible benefit or risk of a multi-national, multi-experimental center like CERN?   Think of the following and attempt to comment on pros and cons for each

a) talking with members of different countries
b) medical technologies
c) the grid
d) the energy needed
e) the construction costs
f) the use of energy
g) the discoveries for physics
h) the age of the universe

http://public.web.cern.ch/public/en/About/About-en.html