At the USCIS in Florida you can bring your cell phone so that is different than going to the embassy in Europe.
According to the USCIS website the I-134 form is making the person who sponsors you, liable in case you end up with no money and are filing for soc. sec., at which time the US government can sue that sponsor for the money and they will!
So I would never sponsor a stranger and neither will many American's do. this is a society of people sueing each other so nobody in their right mind will sponsor a stranger and risk being sued by the government.
Although my friend is a College student, she has many times over the amount to proof she can be over here without being a risk to the government, but just in case we have the I-134 form ready with all the proof needed.
IMO many people never thought, just like me, that so many things were requested before being able to get the greencard after winning the lotery....I guess that many applications will be denied and many people with proof although having a high number will have a chance to obtain a green card. Specially with the jobless rates so high in the USA, I think they will look extra carefully to avoid new soc. sec. application.
The jobless rate in Florida just raised to over 10% and in California it is even higher.
I also read on forums on which many American's are writing that traveling over here on a greencard and leaving right away and staying away for months, can seriously risk you re entering on that green card....so many wanted to obtain a greencard but with shops closing and homes being foreclosed on and rental prices higher than before, it might be difficult for new DV winners to start a life here.
I don't want to scare any one but just be realistic, times have changed and as some one else described before, life is not cheap over here although many things are cheaper over here than in Europe. Gas is way cheaper but you drive way more since public transportation is completely different and only in the Big Cities available....for the rest you have to drive for almost everything.