When I rented to foreigners, they came either as international students or for a techie job in Silicon Valley.  

But now I have a vacancy and an applicant who is a foreign student at a local college.

In this conversation, as foreign as you think it to be, there are places where you {still} are not permitted to apportion the cost of a utility to your tenant if you sub-meter.  

As a small investor managing from afar maybe foreign at first, but get easier as you gain experience.  

While payments up front certainly exist (I have a friend who lives in New York who pays one year up front simply because she just came from a foreign country with no credit), unless you know someone you trust who plays this game as well, I will see if there are alternative tenants as well. 

In the case of my tenants they were foreign nationals who were not allowed to work in the US. 

Unfortunately it's much more difficult to obtain credit and criminal backgrounds on Canadians and other foreigners.  

then if you like the asset and you will be positive year two that's a no brainer for my way of thinking but most folks on this site are buying in the areas of the country were appreciation is a bonus ( at least that what they have been taught and what they repeat)... so its very foreign concept for them to remotely think about a property that is not cash flow positive day one.

I am not a lawyer, nor do I play one on TV- however, this post on the US Treasury site might help answer your question-http://www.treasury.gov/resource-center/faqs/Currency/Pages/legal-tender.aspxThe way I understand it- if as a landlord, you are considered a creditor, you MUST accept cash.

At the time, we were paying below market rents ($2000/mo vs $2600/mo) and knew that the apartment manager was doing everything in their power to get us to move out so that they could rent to foreign students for the summer (at a whopping $3000/mo!).