What is the purpose of these?

http://answers.google.com/answers/threadview?id=473728 
http://answers.google.com/answers/threadview?id=473734
http://answers.google.com/answers/threadview?id=473731

(and many similar questions).

Thanks for accepting my speculation as your answer!

As I mentioned below, it is my belief that the spate of nonsensical
questions may be a series of attempts to check the validity of stolen
credit card numbers. Since the person posting the "question" is not
seeking a genuine answer, the postings are often brief and
meaningless.

Best regards,
pinkfreud

No sensible purpose at all.

They are posted by morons who think that they are being clever.

I believe that some people think they can check the validity of stolen
credit card numbers by posting questions on GA. These people are
wasting their time, since the credit card is not debited until an
answer is posted, and nobody is going to post an official answer to
these nonquestions.

Ah..... I like pinkfreud's answer.... thank you ... you can claim the
fee, if you like, I dont care if your answer is right, I like it ;)

But don't forget...there is a 50 cent listing fee even if an answer is
never posted.  So the cards will be charged.  Google charges us when
we reach $25 or every 30 days even if the bill is only 50 cents. 
Hopefully, GA is checking this out.

The fifty cent listing fee is not debited from the questioner's credit
card at the time a question is posted. These nonsense questions are
intercepted and deleted by the Google Answers Editors, so I presume
that it is unlikely that the fee will ever be charged to the card.

Following on from pinkfreuds last comment.  
Hence the attempts to try and form a sensible question.  

http://answers.google.com/answers/threadview?id=473892
http://answers.google.com/answers/threadview?id=473889

Best regards

THX1138

Thick and fast tonight. Credit card authentication doesn?t ring true,
nor automatic scripting -- both for a pile of reasons. I wondered if
it was a ?challenged? individual, either intellectually or socially,
but there are indicators of reasonable education and intelligence.
Nothing for days then there is a flood, so most likely it is at least
two kids getting together and messing about, gaining kudos rather than
lowering of self-esteem from abusive comments and those of well
intentioned researchers. One could of course divine a pretty exact
profile but it?s not merited.

Hopefully they will eventually get bored and migrate onto something
more constructive such as bending car aerials.

Best

I do like Pinkfreud's hypothesis but, like Guzzi, I don't think that it rings true.

It seems to me that many postings are generated by the same person,
albeit under different names. Surely, he (or they?) would have
discovered by now that this methodology is no use for validating CCs.

My bet that is that it's some kiddy/ies fooling around. He or they are
probably too young to appreciate that their computers can be traced.