The latter two cases indicate social engineering, where the victim has been spied on and cultivated. The Pune man had to have had a reason to believe he had African property and the Worli businessman’s cheaters knew he had recently bought a BMW. In other words, they were not entirely random attacks.
These networks are very well entrenched and have their informants in all major internet companies here. At first I was surprised that this was happening, now after two years I am just trying to gather the evidence so that I have a solid case. The general level of internet literacy is low, so these cybercriminals think that they can get away with it (and they usually do). In Europe, USA, Canada, cyber criminals have served jail terms, so it is safer with businesses there.
All this has badly hampered the growth of internet in India. If you are sure that your emails are being intercepted, will you send any important information over email? The signature of these cybercriminals is blank calls from non existent phone numbers. Some Indian internet companies turn a blind eye to these criminal activities of their employees, but they do not realize that in the long run, they lose both money and goodwill. If your customers are getting hurt financially by these criminals, they will spend less money with you and move their business to other vendors.
After a time, it is easy to detect these activities, the criminals are humans and they start leaving evidence. Some of these criminal networks seem to be hired by big global companies. Unfortunately, some Indian internet companies are not very cooperative and do not take any action to prevent this problem, which also damages the companies in the long term.