The Better Business Bureau is warning Facebook users that sharing a certain kind of attention-grabbing post might put their friends at risk of falling victim to a scam. You may find a gut-wrenching post about an injured, lost pet or a missing child grabs your attention. You want to help, so you share the post on your own profile.

But at some point, the scammer changes the original post to a deceptive rental ad or sometimes to a link pointing to a survey that "guarantees" a cash prize. Now, your friends think you have recommended that content. BBB Investigator Don O’Brien says another one making the rounds right now is one that claims they are trying to bust a catalytic converter thief.

This scheme has many variations, but the common thread is the emotionality or urgency of the message that encourages concerned people to share the news with their friends. Scammers sometimes also turn comments off on the posts so other group members can't out them.