Can we all agree that "service" accounts suck from a security perspective. Those are the accounts that you set up so what system/service can talk to another one. Often this will be a database connection so the application uses one account (and thus one connection pool) to access the database. These service accounts are sometimes unique to a service or application, but often its a standard service account for anything that needs to connect to a system.
The problem with that is that you've therefore got security defined at the service account level, not at all based on the users actually using it. So if that database contains the personal information of every customer then you are relying on the application to ensure that they only display the information for a given customer, the security isn't with the data its with the application.
The scope and level of protection should be specific and appropriate to the asset at risk.
Service accounts break this commandment as they take the most valuable asset (the data) and effectively remove security scope and place it in the application. What needs to happen is that the original requestor of the information is authenticated at all levels, like with OAuth, so if I'm only allowed to see my data then if someone makes an error in the application code, or I run a Bobby Drop Tables attack, my "Select *" only returns my records.
This changes a lot of things, connection pooling for starters, but when you are looking at reporting in particular we have to get away from technologies that force systems accounts and therefore require multiple security models to be implemented within the consumption layer.
The appropriate level to protect data is at the data level and the scope is with the data only by shifting our perception of data from being about service accounts and databases to being about data being the asset can we start building security models that actually secure data as an asset.
Today most data technologies assume service accounts, this means that most data technologies don't think that data is an asset. This has to change.