Examination of internet records in order to reveal the identity of an anonymous poster is defined as
doxing
filtering
spamming
hacking

Doxing

Explanation: Doxing which is also referred as doxxing is defined as the revealing or publishing of the private records or information to the public.It is considered as the illegal practice which is base on the the internet service.The publicizing of the private data or confidential information is punishable offence.

Other options are incorrect because filtering is the elimination of the not required content, spamming is the activity of sending undesired bulk messages and hacking is the attacking of the system using false means to corrupt and steal data.Thus the correct option is doxing.