Well, after Clapper v. Amnesty International, it’s more than the price of a plane ticket.
If the law were otherwise, an enterprising plaintiff would be able to secure a lower standard for Article III standing simply by making an expenditure based on a nonparanoid fear. As Judge Raggi accurately noted, under the Second Circuit panel’s reasoning, respondents could, “for the price of a plane ticket, . . . transform their standing burden from one requiring a showing of actual or imminent . . . interception to one requiring a showing that their subjective fear of such interception is not fanciful, irrational, or clearly unreasonable.” 6