posted by in Amsterdam forum
Take a look at some advice on this here: http://housing.justlanded.com/en/stay_safe_online
Let me guess, they have a phone number starting something like this +44 70, a Yahoo email address and is very concerned about being conned himself (which is why he needs a deposit). Probably has a sick mother as well?
Quickest way to smoke them out is to say you have friend who will visit the appartment and ask them to organise to have someone there to show it to them. If they cannot do this, then they are not renting an appartment.