This BBC Radio programme, The Sociology of the 1% of the 1% (stream available for a couple of weeks, and there’s also a podcast link at the bottom of the page), is relevant, I think.
To summarise: Big Data can track the super-rich as easily as any other social group, perhaps more easily than anyone else, since their mere existence distorts the economy all around them. The money of the super-rich billionaires is typically managed by merely rich financial advisors and accountants (defined by the study mentioned in the programme as those with over a million in investible assets), and in several cities the haunts of the rich are being taken over by these financial institutions, with classic townhouses being hollowed out and filled with financial servers.
In fact, in the cities with the greatest concentration of billionaires (e.g. London with 77 billionaires), even the rich are finding it hard to afford to live, as the billionaires build up and down in their quest to avoid the ordinary people around them, warping local property prices to levels that only billionaires can afford. Their quest for exclusivity leads to them being escorted by bodyguards whenever they visit the less “safe” areas of the city (e.g. Notting Hill, a thoroughly gentrified part of London), flying by helicopter further afield, and holidays on their €50 million yachts, safely insulated from the hoi polloi.
