Earlier quoted context omitted.
I know it's not perfect, but if you use Amazon's Alexa and know an Alexa you can change the wake phrase to a few others (iirc "echo" and "amazon" are among the choices).
It’s not just a question of being a friend or family members name name. It’s also easy for a YouTube video etc to accidentally include say “Alexia turn off the lights” as part of seemingly innocent dialog that nobody building it thinks is going to cause a problem.
I'm assuming part of it is that it's gotten very good at recognising who is speaking. E.g. my son and I tested the limits of it a while back by changing voices (it still correctly identified my son when he tried to change his voice), mixing and matching (I'd say "Alexa" and he would say "who am I?" and vice versa; Alexa would recognise whomever said "Alexa" irrespective of who spoke what followed). So it'll usually know if whomever is saying "Alexa" is a known member of the household, which would seem like a good indicator to increase the threshold for how clearly the phrase is spoken before activating.