There's an excellent discussion and rebuttal of this objection by DonaldM (henceforth DM) at Uncommon Descent. DM labels the objection the EC-EE (Extraordinary Claims-Extraordinary Evidence) objection and reveals it to be a rather empty assertion.
For example, he notes that the term "extraordinary" in both EC and EE is so vague as to be meaningless. It is, moreover, a term that's worldview dependent. The claim that Jesus performed miracles is not at all extraordinary to the community of Christian theists but is extraordinary indeed for naturalistic materialists. Put differently, if a personal God exists the claim that miracles happened is not necessarily surprising. If God doesn't exist then a miracle would be surprising, of course, but one cannot assume that God doesn't exist and then conclude that miracle claims are "extraordinary" since that would beg the question.
Even setting that aside, the EC-EE objection cuts both ways. Intelligent Design advocates argue that the specified complexity (information) content of living cells is so improbable on naturalism as to make the claim that natural processes gave rise to it without the benefit of intelligent input an unimaginably extraordinary hypothesis. Where is the extraordinary evidence to support it? Yet, despite the utter paucity of evidence that blind, purposeless forces can produce meaningful information the very people who believe it happened often treat with scorn anyone who doubts it, and they demand of them "extraordinary evidence" that an intelligence guided the process while proffering none in favor of their own belief.
VJTorley has it right in the comments section of DM's post when he states that:
[W]hat I would say is not that extraordinary claims require extraordinary evidence (which is a very vague term), but that they require evidence that renders alternative hypotheses very unlikely.In the case of the resurrection of Jesus and of the fine-tuning of the cosmos the naturalistic explanations are so implausible that the only reason anyone would believe them is that they have an apriori commitment to naturalism. If, however, one suspends one's apriori commitments and leaves open the question of whether there is or is not a God the evidence for the resurrection and the fine-tuning of the universe certainly supports the conclusion that a miracle occurred in the first case and that a mind was involved in the second.