It only becomes problematic when you consider that the user is getting themselves into a situation that they do not fully understand and potentially cannot easily back themselves out of.

With drugs that have a high potential to cause harm, we typically force the consumer to consult a professional before allowing them to proceed. Tech is still in the era of patent medicines.

There's no such thing. Email breaks the concept of email security.

LI, Google and Facebook have always wanted your third-party email credentials for Friend Finder-style features. The only difference is that this time we cannot even hope that they delete them after logging in once. Security-wise, it's all the same.