Like OpenPGP Web-of-Trust Public Keys Infrastructure… trust user public keys, not a photo/nickname profile… BTW, the TOFU concept is also an interesting one…
Walfield, N.H. and Koch, W. (2016). TOFU for OpenPGP. Proceedings of the 9th European Workshop on System Security, pp.1–6. doi:https://doi.org/10.1145/2905760.2905761.