This. Either everyone should be notified before the first google analytics transmission so that they can choose to opt in our out. Or the default should be off and maybe on new installs they can choose to opt in. At the opt in/out dialog (when you give the users a choice) you can make the default to opt-in, but having the default as opt-in without any input from the user is bad form. It is similar to spammers calling your e-mail address "double opt-in" because they got you to open an e-mail and you didn't click the unsubscribe link.
How should this be handled if the software in question is a server daemon? I want the users to make an explicit choice but it's not obvious what's the best way to do that.
Or if you want to cover existing users, just ask during the first interactive invocation, when there is no prior user chosen setting (works for new installs too)...
pseudocode:
choice = no
if $brew_prefix/etc/homebrew.yaml:
choice = read analytics $brew_prefix/etc/homebrew.yaml
else:
if interactive-tty and cmd != "--prefix":
choice = ask-user "enable anonymous analytics (it helps us!)? Y/N: "
write analytics=<choice> $brew_prefix/etc/homebrew.yaml
if choice == yes:
enable-analytics
I feel like on update would be better. Answering a yes/no/never isn't that much of an ask, I don't think. And that way you get a chance to use the software before you have to make a decision.
