It is "ageism" and it's ... annoying! Personally, I'd shoot off a letter to that company and I'd wage a campaign against them. I've turned several folks from shopping at a certain store over the past several years, so you can have an impact.
I can understand wanting to protect our seniors, but isn't that the responsibility of their family? Not corperate companies. Besides, you can go to loads of public libraries, internet cafes, etc and use the internet on someone else's computer.
Where does it end? Should we ID everyone who shops and if they are buying what appears to be wasteful junk, refuse to sell to them because they are seniors and might be wasting their food money?
The world is a weird place.