But a PRISM 702 doesn't even apply while you access your cloud data; it's simply an authorisation to go in and take any or all of it (and then monitor your later accesses) regardless of whether you've even been near it recently or not. In any case, even if a PRISM search is a border search (not necessarily a search at the border) it's certainly not a search conducted abroad, at least when the servers with the user data are inside the US.