OK, another rant from me, but I'll try to keep this one brief.
I just signed up for "Stumbleupon " because I want to see whether it can lead me to new websites I might like. There's a social aspect to it, too, so that you can see what websites your friends like. Great! And it will look at your Gmail contacts to help you find your friends. Wonderful!
Herein lies the rub: it imports your list of friend email addresses and it tells you it's going to find your friends among the thousands of people who are already registered. But then, once it has your list, it tells you that it will automatically connect you to those who are already registered but for the people who are not registered it will send them an email invitation.
I personally don't mind (and even like) invitations sent from my friends, unless they're for commercial services or the like. But I don't presume that everyone I know is going to welcome an invitation to a service I'm not even sure I like yet. I'd rather that it just checked its own database but not send out invitations. But it tells me it's going to do both at once.
At least it warned me. I said "No." Please do not spam my friends.
But someone being less careful might easily click through and send the message to everyone. Because earlier in the process it seemed like it was just going to check against its own list of members.
Stumbleupon: please just give the option for me to discover who is already signed up.
Any of you who are already in Stumbleupon, please feel free to add me. Use the email address from my "Contact Me" page linked from my sidebar.