In answer to this question; the phrasing could be more specific. I believe he's referencing the number of seniors who are targets for scams like these and would benefit from a card like this. In this case, the question is: how many seniors are there in America, who are living alone, with some cognitive decline, and highly susceptible to fraud and scams?

See this Bloomberg piece -- 2010 estimates that financial abuse victimizes 1 in 5 elderly; about 7.3 million senior citizens have reported being taken advantage of. http://www.bloomberg.com/news/2010-06-15/financial-abuse-vic...

The scary part is that it's likely much, much higher (the number of people being taken advantage of) -- because so much of it goes undetected, or worse, unreported.