Even if they are just using it to answer..Yahoo does not allow spammers once it is brought to their attention and now that they are affiliated with AT&T its even worse.
Yahoo can take away their account and put them on a list of spammers reported nation wide and  make it hard for them to get another account in that name. 
I realize that if a spammer wants to spam bad enuff they will just get another account  in a different name, but at least it will  make them think twice about coming here if they think that they will be reported every time.

 

“For those who believe, no proof is necessary. For those who don't believe, no proof is possible.”

[Stuart Chase]