Wow. It seems like everyone is having this problem! This serial inviter needs to like sip some Bubble Tea and go into time out with the Frogs for a while.
I block the worst of the spammers. Nobody in the world is just so awesome that I'm willing to put up with spam from them just so I can be treated to other interactions with them as well.
There have been some server issues -- sometimes that pulls back up something old and treats it as something new. But when you go to send requests, it provides only your friend list as options.
We're talking people who go through and invite hundreds of people to a group, repeatedly. Do you really think they will remember special snowflake you? Far easier to block/unblock and get off the friends list.
Actually I do and have been remembered. I have let them know when they're inviting people to groups to ask themselves I wonder if Eye Wonder would want to be invited to this group. I've never had a problem after that.
I don't really like the "Ignore the invite and they can't send you another solution." I don't like to have invites cluttering up my notifications page. If there's an invite, the OCD part of my brain wants to deal with it and have it gone.
I agree with Aurora. Also, I don't like being passive aggressive (or is it just passive): essentially sticking my fingers in my ears and going "lalalalaIcan'thearyouuuuu."
It would be nice if there were a "decline with prejudice" option, so that another invite could not be issued.