The value of not knowing something illuminates some basic assumptions about knowledge and allows us to ask a series of interesting questions about how the information society will develop.  Our relationship with knowledge is an uneasy one. As we progress the cost of acquiring knowledge seems to be sinking, and the choice of what knowledge to pursue becomes more pronounced. We can imagine a world in which we could find out a whole range of things, at a moderate cost, but will choose not to because we believe that it would be wrong to attempt to know those things. That would be consistent with how knowledge has been viewed over the centuries, and would require us to develop a sense of when it is morally defensible to choose ignorance over knowledge. The value of not knowing something illuminates some basic assumptions about knowledge and allows us to ask a series of interesting questions about how the information society will develop. This talk will examine a number of ways in which this tension can play out.