A few thoughts on the idea that domains should be everyone's "internet handles"
xn--gckvb8fzb.com
xn--gckvb8fzb.com
Even the casuals know about the general problems of user handles being squatted and such, and thus have little problem finding alternatives (put in an extra letter or number or two) and leaving the verification of account ownership to the platforms themselves, so the problem domains could be used to fix here just isn't that big after all.
Internet Handles