I honestly had to look up the meaning of “strapline” and how it differentiates from a brand, vision or missions. Wikipedia redirected me to Advertising slogan and told me:
Advertising slogans are short, memorable groups of words used in advertising campaigns. The advertising phrases are means of drawing attention to one distinctive feature (an aspect of a product). The purpose is to emphasize a phrase that an entity wishes to be remembered by; Particularly, for marketing a specific corporate image; Or, connection to a business product or consumer base.
Which raised an eye brow and I think this is very a lot of the current confusion and discussion comes from: What’s the advertising campaign? Who are we trying to reach and advertise to? And why and why should they care? What would distinct aspect of SAFE would they care and know about?
The article goes one to explain that very often claims start out as part of an initial advertising campaign and turning into a brand-wide identity ones it catches on – I believe “Just do it” is such an example. But I feel we are skipping an important step here: we try to define the brand before we even have any campaign (answering the aforementioned questions) and compare them to claims that without their initial campaigns make little sense.
I truly thought “SAFE” was an abbreviation for “Secure Access for Everyone” – why else spell it all UPPERCASE? But depending on who you talk to “Secure” (as well as “safe”) have very distinctly different meanings – especially in regards to technology/the internet. Secure as in TLS? As in secure coding? Safe as in “condoms”? Where does “privacy” come in there? Does that have to do with “safe” or secure? Facebook is secure – yet privacy is violated all the time.
I think one problem I have with those is that you first have to explain how the current internet is not or you are facing a crowd, which knows but comes with a lot of expectations (TOR users, Crytpo- and Blockchain-Experts). The SafeNetwork is a “the internet reinvented” or next generation but much more than it is being build upon a new set of guiding ideas and principles, which make the heart of the entire endeavor: this is not HTTP/2 (which is also ‘secure’ by default).
I really like that Brand Brief document, the vision, position and guiding principles are amazing, yet none of the proposed claims/straplines capture this. I like the word “safe” because it provides an emotion: “feeling safe”, “stay safe”, “be safe” – and a lot of the guiding principle ultimately are about that: not being violated. No violation of your privacy, of your communication and not even in the processes of how these things come about and are decided upon in the first place (RFCs, open communication even on funding). There are plenty of other technologies and project claiming to reinvent the internet and provide safe cloud solution blah, but IMHO this is the true heart – This is the WHY @Jabba was referencing with the Simon Sinek talk (seriously great talk!).
I do feel that the claim needs to convey that. Not only the technology but exactly those human aspects that we care very deeply about and make us even have these lengthy discussions. Like Mozilla stands for an “open web” and their entire company culture and way to work incorporates that. I’d love for us to stand for the “safe web” (like “safe sex” 
) – but this will require some more pushing of our side to define the terms better.