At first we blamed the neighborhood cat. It wasn't the cat. The birds were leaving the feeders, satiated I presume, and flying into our windows. If they hit the window hard enough, they literally killed themselves. The unanticipated consequence was avian demise.
Information professionals encounter unintended consequences with surprising regularity.
Take productivity of online researchers as one example. The plethora of informational resources on the Internet frequently increases the time it takes to complete a research project. There are more sources to examine, more leads to run down. Evaluating the validity of the information found takes time as well. Questions posted to library listservs in the attempt to short-circuit the research process sometimes produce lists of even more places to look.