Agreed. That's why I believe it might be super handy if every or at least many phones had this in place so that you don't really stand out. At least every phone using an alternate OS. If all the mainstream operating systems had this I would expect an arms race between the OS devs and the forensics device devs.

As a side note, this would not necessarily be only used for law enforcement authorities. It could be that an armed phone thief requires you to unlock your phone. Sending a duress message, maybe even camera footage, GPS coordinates could be quite useful in the event you vanish. Teaching your kids to use this feature on their phones could also be very beneficial.