Getty/Picscout can collect. They are the experts! But , in my opinion, they cannot sue. Only the owner of the copyright or the owner of the exclusive license can sue. In this case, the artist MAY have transferred these rights to the company in Bath , England. But then again, the artists may not even have done this . The stock photo companies are subcontracting the extortion letters/ collection part of the business to Picscout/Getty. But they cannot subcontract/ transfer the right to sue. This is not a transferable right.