More people have access to the Internet via cell phones worldwide than have access to a flush toilet.
Untrue. I know there is a dailymail article which made a similar claim, But there is a flaw in the article and your statement is not the same as dailymail's.
First of all, It's true that there are 6 billion mobile subscription in the world. But it does not necessarily indicate that 6 billion people held each subscription.
In case of United States, There are 321.7M wireless subscriber as of JUN 12. And guess what? There are only 313,914,040(est) people in the US as of 2012.
And It's not a rare event. In Hong Kong, There are over 13 million wireless subscriber(2011) but the population of Hong Kong barely exceeded 7m(2011).
Therefore, The number of actual phone holder must be quite lower than 6 billion. It could be lower than 4.5 billion which is the number of people who have an access to flush toilet.
And most of 6 billion phones are not even smartphone. A cumulative smartphone sales figure won't pass the 2 billion bar in this year. In other words, there are at best 1-1.5 billion people who have a smartphone and internet connection service provided by network operator. Plus, there are some people who has a phone but not a computer especially in underdeveloped countries, but computer owners usually have a phone nowadays.
Therefore, a number of flush toilet user must be 2-3 times higher than a number of internet users.
Read the link.
Stop and think, young man. 5 volts at half an amp, or 2.5 watts. A standard bike headlight is about 3 watts, whatever shall we do???
It's not widely accepted. Can you make a claim that most of the people who doesn't have an access to electricity have those kind of bicycle-powered charger?
Of course you cannot. Therefore, there are still electricity related issues out there.
some people have made a business out of using a solar panel to charge phones for others.
Think about cell tower. It's very common that people don't have an access to electricity because their closest electricity line is at least 20 miles away. And in this case, There will be no power to activate the cell tower they need. Powering it up by solar panel? Hello? Their governments don't have money to spend on electricity line.