The use of big data to target electorates has been used for centuries now. There are many opinions on this tactic which can range from one end of the scale to the other. Most people would say that targeting specific individuals to campaign a candidate is wrong. Just because it puts social profiling into action. Yet, all the access ever needed to see what a person may be interested, thinks, and believes in is available on social media websites like Facebook.
Other people may argue that it is a useful tactic that challenges many people as to why they think or believe the things that they do in regards to candidates and who they want to vote for. Most volunteers get to see this side of the contribution to whichever campaign they may be helping.
In the end, targeting electorates is technically profiling people into groups, which will always be a touchy subject. But I think with social mediums available that do all the information work for us, it becomes less ethical to deal with. People forget that they put their whole life on social media website after they complain about having their personal information rights violated.