I remember when LinkedIn had an anti-pattern of displaying a check list of your gmail contacts and asking which of them you want to connect with. These were all

I remember when LinkedIn had an anti-pattern of displaying a check list of your gmail contacts and asking which of them you want to connect with. These were all unchecked by default. But under the fold - that is, you needed to scroll down to see them - were all the rest of your contacts, only these were all checked. If you just went with what was displayed without scrolling down and unchecking the rest, you would unintentionally blast your entire contact list with contact requests. That was everyone in your contact list, whether appropriate or not: your dog groomer, people you were in a lawsuit with, whoever. I never did figure out how they were able to get our email contact lists. I vaguely remember reading about web-scraping shenanigans. I for one never knowingly gave them access.