I recently tried disabling notification in LinkedIn. The designers and engineers working there who created the notifications settings are truly evil. You have to go through 14 categories. Some of them let you toggle the whole category at once, some don't. Some categories are split into 8 more subcategories.
To this day I do not have a LinkedIn account because they have historically been the most aggressive spammers of any company. The year I graduated college, almost 2/3 of the e-mails I received were LinkedIn spam.