The killer these days is places demanding your email prior to giving you a shipping estimate. Particularly annoying if you live somewhere where shipping costs vary greatly between providers.

I hate hate hate this - especially because my browser autofills my email with my address. My flow is to autofill, then go back and change the email to gibberish. Sometimes that doesn't work and I get some un-asked for promotion anyway.

I think I should have to at least click a button for some company to be able to send me what is clearly a marketing email.

Not allowed in Europe, afaik.