A recent article post here a user indicated that he has mulitiple vendor specific aliases to track who sells his email address.
My issue somewhat relates to aliases as well. I am not sure if this scenario is common to others but I thought discussing this might open some channels.
As a consultant, I often take on an email address/alias name within and organzations domain. While working with this organiztion this is handy and makes me identifiable to others within the organization. Many times though my research requires me to join other forums and groups. Lets take one as an example, SE (StackExchange) and its various forums/blogs whatever they identify these unique classifications as, are great places to research or ask technical questions when solving or developing code, working on servers, networks, etc. etc. There are many others as well.
I do like having a single identity in the SE to keep my research centerally located with that one log on. I do not necessarily want it linked to my gmail account, or yahoo account or my microsoft account, let alone the account I use to connect an xBox for my grand kids, or the one I use so my wife's computer can use Office 365, etc. etc. Worse, now I have to have a account for home PC, differnet from my office PC, or these systems are tied together.
I have a significantly growing concern about the "single logon" approach to internet space management. If things continue to move this way I would much rather have an OS based app that allows to me to assign which environments will use a single sign on. When I log into my PC at home, I can review which apps will authenticate me and which credentials I have assigned to them, not he portal itself, asking Google, or one of the other environments, if I am ok to access.