Shares of Care.com (CRCM), the operator of an online marketplace for finding and managing family care, are sliding after short seller “Batman Research” published a report accusing the company of “non-existent to minimal” vetting of its caregivers. The research firm states in its report that it believes at least three children have been killed by Care.com babysitters, who have also allegedly “repeatedly abused children.” Care.com background checks “are not reliable” and the firm also alleges that “the majority of Care.com’s ‘14.2 million registered families and 11.0 million caregivers’ do not exist and other key metrics are incorrect.” WHAT’S NOTABLE: The Twitter account that was used to promote the report, @BatmanResearch, has 7 tweets and 240 followers at the time of this writing. PRICE ACTION: Following the circulation of the critical report earlier this morning, Care.com shares are down 89c, or 5.7%, to $14.75.