Google before anything

Warning! This post is very old and may contain information or opinions that are no longer valid or embarrassing.

I have been receiving large number of invitations in the past months. I have never responded to those invitations, but they are very annoying and it seems like my friends are spamming me with those invitations.

Yesterday, it drove me nuts. The invitations are repeating every few days, warning me that I am not responding to requests and keeps on resending the requests!

Anyways, a simple google search shows that does both; scam and spam.

Now, to google before every web service they join is too much trouble for my ''Fwd:Fwd:friends''.

How can I tell them to be a little bit more cautious?

UPDATE: Ok, solution is very simple. Create a filter rule in your mail application to move any mail that matches (in the from: field) to Trash. This will not solve the spam, but at least will end the crazy requests.