That's why the only email subscription service on my site is completely transparent and details exactly what we're storing, and it's impossible to click by accident. Everything I do for myself I try to build like a service I'd like to use myself. But the second managers or marketers are involved it's all out the window. I remember early in my career my boss had me add every email included in a TED booklet to their marketing email list. I told him that morality issues aside he could likely catch a fine for that, especially since the type of people listed in a TED booklet are likely more litigious than the average bear. Didn't care, wanted more eyes on the marketing.