Why Are Dead People Liking Stuff On Facebook?
readwrite.com/2012/12/11/why-are-dead-people-liking-stuff-on-facebook
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
A Facebook spokesman says the likes from dead people can happen if an account doesnt get memorialized (meaning someone informs Facebook that the account-holder has died). If nobody tells Facebook that the account-holder is dead, Facebook just keeps operating on the assumption the person is alive.
In that case, someones likes from months and months ago can still keep surfacing in the news feeds of their friends, since Facebook recycles likes long after they first occur. Who knew?