The most heartbreaking part of this is these people are actually typically in poor financial situation (looking for a job) and are on an extreme emotional rollercoaster (from not having a job to getting a fantastic job to not having it again and loosing their last money).
The solution to not get scammed is to know at least a little bit how companies operate, but in large population there will always be gullible/oblivious people. Nobody ever will ask you to buy a corporate computer with your own card and then ship it to the office to have configuration on it done. That's just too much hassle. But too many people just don't understand this or are too excited to question it.
What I would ask companies to do is to start having an official hiring rules page on their corporate website that explains the process to ensure hiring process is genuine.