I've signed up for a cool job website that, unfortunately, asks you if you want to "invite your friends", and if you say so, you can give them access to your Gmail contacts to send the invite.

However, contrary to what everyone would be expecting, they don't give you a list of who you want to invite; instead, they simply directly send spam to your entire contact list, like old-fashioned Outlook viruses. When you complain about this with them, they simply say "we will check the application and see if there is anything that might be confusing for the users".

For me and some other friends (that felt for the same prank), this is a clear break on web best practices and a big disrespect on the users' trust. Thus, I would like to know what can we do to stop the website of using Gmail/Yahoo/Outlook APIs to send spam this way.

P.S.: I wonder what would happen if I've given this website the access to post in my Facebook timeline as well. I've got a couple of calls from relatives asking about the email and I wonder how many unrelated people got this spam, like HR addresses from my past and whatnot.