While designers like myself often think of ourselves as the victims here, often the companies are victims as well. Many of them spent money, good money in some cases, to end up with a shady designer or agency ripping off work and selling it as their own. The client is not only left without a mark to represent their brand, having to start all over but they've lost the money they already spent and risk lawsuits for the infringement. This is another good reason to find a reputable designer you can trust. A local designer you've met face to face and know a real name and address will help tremendously as many shady "designers" like to hide behind the anonymity of the internet. This is also the reason why many crowd-sourced services and competitions have been caught with blatantly stolen logos for sale.