Apparently, Yahoo! has software that automatically kills applicants if the group administrator doesn't intervene in two weeks. Either that, or they have the pronoun problem properly known as an ambiguous antecedent.
Here's their language:
Pending members require your approval. If you take no action, they will automatically expire after 14 days.
The "they" appears to apply to pending members, which makes us wonder what sort of automatic death might occur... sudden cardiac arrest? Futuristic disintegration? Total petrification?
Of course, they probably meant the requests would expire after 14 days. That would have been a good thing to write.