One other thing about badges this year, due to the Covid checks, you actually have to show your Govt ID and it must match the name on any Covid test or documentation you provide. While it doesn't say they will check your badge against this info, one would think this is one way they can can do so this year.
Agreed though that in years past, they have never done anything to check your badge name to who you really are, this year actually presents a way for them to do so. I wonder if the sellers are telling the folks who buy the badges this, I'm guessing not.
Finally, I recall vaguely (although its been awhile) that prior to checking out buying badges, you usually click a box saying that you agree to the terms and conditions for SDCC's policies (which include not selling the badges). That's your contract signing there.