I.e., when a novel came out in 2006, but it's P.I. main character has a pager and a modem. I'm like, "What? What ficken year is it??? 1999?"
It matters, oh authors! If the tech in your book doesn't match the tech common the year your book comes out, please actually STATE what year your novel is set in in the text of the novel. I don't care if there are vampires running around, that pager throws me out of the story and makes me question everything you wrote. WHEN is this story? Where are their CELL PHONES?? OMG, SO ANNOYING.