I agree with Ralle from Netzbuch - Riya and similar ideas are definitely very strange and the reaction to them, or rather the enthusiasm for them, shows a very unreflective use of these systems by users. I find it surprising how much information users voluntarily put about themselves into the various allegedly social software products - and thus give themselves and their environment to the advertising partners and potentially everyone else with access to the data (law enforcement agencies, burglars, data thieves). More and more networking and less and less privacy, that seems to be the motto of Web 2.0 for some.