Getting added to facebook groups without my permission

I have noticed that I'm getting added to facebook groups that I've never heard of without having accepted any requests. When I checked the groups, there was nothing that I was particularly interested in and I didn't want to be part of that group anyway. I've had to click on the link for "Leave this group" so that I'm no longer part of the group.

To me it's a sort of spam which facebook needs to fix. I don't like the idea that anyone who I'm friends with can just add me to some weird and random group without my authorisation.

Is there a feature to block this?