As others have noted this is easy enough to thwart if you prepare, it will only catch the unsophisticated. So they aren't going to catch terrorists with this,

As others have noted this is easy enough to thwart if you prepare, it will only catch the unsophisticated. So they aren't going to catch terrorists with this, but it probably will catch a few people intending to work while on a holiday visa. But it would be nice if the phone manufacturers made it easier to side step. Android is close already: it has multiple users. If it allowed you to hide a user (so you had to type in a name, for example), it would be mostly there. One thing I really wish they would provide is a decent backup service, ie something that allowed you to backup everything on the phone, to an encrypted binary blob. Mainly I want this because having a backup that allows me to restore my data if the phone gets destroyed would help sleep easier at night, but of course it also solves this problem too: backup the phone to a hidden cloud account, factory reset it, restore it on arrival.