What is a paradox?

I'm sometimes puzzled by how I apply certain concepts and then realise I might be using them all wrong. For instance how I use "paradox" in a work-in-progress (which will be part of a mighty interesting Norwegian anthology to be published in the fall):

The opportunity to design personal performances through edited pieces of textual, visual and sonic elements denotes that the individual has control with her or his own presentation, but only to some degree. As such online personal practices are characterised by a control-paradox: on the one hand individuals can construct filtered yet accurate and beneficial self-presentations (both socially and professionally); and on the other hand, once published, users have little control over content and little chance of preventing abuse such as republishing without consent.

Considering actual definitions of "paradox" I am not at all sure this is the concept I should be using.

Paradox: an argument which seems to justify a self-contradictory conclusion by using valid deductions from acceptable premises.

Other definitions.

By the way, the actual article concerns digital dilemmas: briefly summarised:

Users of social network services experience that having a publicly available online presence is meaningful. However, sharing texts, photos, videos, communicative acts and visualisations of social networks with known and unknown others may contest issues of privacy. Users consequently face a dilemma with two unfavourable options: protecting one’s privacy by not using social network services, despite potentially undesirable personal and social consequences. Or, alternatively, choosing to have an online presence and hence put one’s privacy at risk.