Facebook "Error message [404] 404 Not Found" email messages

This one has me scratching my head.. a series of emails this morning with subjects similar to the following:

Error message [404] 404 Not Found for m.facebook.com/media/set/?set=a.[redacted].8100.100000762125833
Error message [404] 404 Not Found for m.facebook.com/pokes/?refid=7
Error message [404] 404 Not Found for m.facebook.com/home.php?sk=photodash

The emails appear to originate from a Yahoo! IP address, the sender's email address matches a registered Facebook account and in one case the URL in the subject links to a gallery from the same user. But I don't know who these people are, and the email address sent to is a rarely used one that has NEVER been used for Facebook.

In most cases the email is blank, in one case there is a photograph of a BlackBerry, apparently taken yesterday from a Samsung GT-C6625 (an oldish Windows Mobile device). The IP headers indicate that this is maybe coming through a mobile version of Yahoo! mail. An infected mobile phone perhaps?

It's all kind of odd, perhaps it is the precursor to something else?