Permissions for guests (and anonymous) settings are
"can view profiles, memberlist, who is online = NEVER"
If I view a 3.1.x board as a guest I see in topics in the profile the contact info for messengers and websites of users. Not cool.
Every guest can see your messengers IDs, Skype name and your weblink. If you click e.g. on ICQ contact info the profile of this user is shown. Same with Skype or other messengers.
If memberlists are not public we imho have to protect all user data and messenger contacts, too. All profile data of members should be hidden by default except the Administration, if memberlist is not visible for guests. If someone of the members wishes to share it, he should be able to activate this by himself, as it is on social media platforms.
You don't know what happens tomorrow with EU laws about privacy. New legislation relating to privacy are enacted each year. In addition, in every country there are different, in Germany it is a hot topic. A lot of lawyers are on the hunt for people who have a breach of the law on their websites, and make a lot of money with little effort.
Data we wrote in our profiles 10 years before are now visible, are now linked with other sites (Skype, Facebook...) where someone can find out our real data. 10 years ago we had a different understanding of security (and we had no Facebook or Google). You can do a lot with a name, a location and a date of birth...
And with phpBB 2.x/3.0.x we had made changes by ourself on core files. With 3.1.x/3.2.x we want to avoid to edit core files.
Public display of user profile data is dangerous today. So I wish to have permissions for guest to hide user defined profile fields, too. To hide names, avatars, locations, messengers, who is online, birthdays, rank lists and anything else about users on a board.
It should be a core feature, not an extension, because if a developer of extensions don't want to update his software you can not hold your security level of your board, if phpBB is kept actual.
I hope I am not alone and suggest you to vote for this important addition of permissions