An encroachment is something that intrudes and has the power to influence whatever it encounters. Some might consider text messaging to be an encroachment of impersonal technology on true, heartfelt interactions.
Encroachment carries the sense of something slowly creeping into something else's space, either literally or figuratively. An encroachment can be of the physical variety, such as the encroachment of new development into a beautiful coastal area. Encroachment typically has a slightly a negative meaning, hinting at something that intrudes on something and then spoils it in some way.