Bewenched - 3:14 am on Nov 21, 2012 (gmt 0)
I've been getting a lot of them as well even though our site isn't really set up for phone traffic.
Haven't blocked them yet and I don't really want to prevent all hotlinking... I like when a forum uses an image or someones little home page... those are fine.... I track them, and add a small banner to the bottom of it after a while so anyone viewing knows where it came from and hopefully I get some traffic out of it.