Christian Decker wrote this in the late evening:

Many Web Applications nowadays have the option to import your contacts from you other accounts like Gmail, Hotmail, MSN, MySpace, you name it. It usually is a nice feature for both the users and the owners of the application, as the users can get quickly connected to their contacts, while the owner rapidly gets new users. But stop! Not all “import contacts” options are the same, there are the good guys and the bad boys:
- The good guys don’t ask you immediately to import contacts and certainly don’t force you to. They give you the option later on or they let you skip it, maybe you’ll do it later. What they certainly don’t do is automatically invite every contact you import by sending them yet another stupid email, or send friend requests in the case of social networks. These are absolute nonos! Don’t ever do anything the user is not asking for.
- Then there are the bad boys, their mentality is best summed up as “All your contacts are belong to us!“, no really they don’t give you the option to skip import or tell you that if you don’t do it right now you won’t be able later. On top of this thy will send an invitation to everyone on your list and keep hammering them with updates, possibly citing you as the sender. These people will get pissed and at least delete you from their contact list, if not worse.
I had this problem once in the last few months and I can’t tell you how embarrassed I was to find out that an invitation has been sent to all my work colleagues. So please, please, please web developers be nice and give me a moderate import contacts, even if an aggressive import can fastly grow the number of your users, it will piss off ten times more!