Problem:
Title for references are formatted automatically in lower case.
Minimal Working Example:
\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{RN518,
author = {Naughton, J.},
title = {What you really need to know about the Internet: From Gutenberg to Zuckerberg},
publisher = {Quercus},
address = {London},
year = {2012}
}
\end{filecontents}
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[swedish,english]{babel}
\usepackage[natbibapa]{apacite}
\bibliographystyle{apacite}
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque varius maximus enim in scelerisque. Aliquam dictum mollis fringilla. Donec eu ullamcorper erat. Curabitur sit amet dolor eget tellus convallis rutrum consectetur elementum ligula. In a cursus magna. Maecenas nec tristique tortor. \citep{RN518}.
\bibliography{\jobname}
\end{document}
The title is:
What you really need to know about the Internet: From Gutenberg to Zuckerberg
But renders as (notice the words Internet, Gutenberg, Zuckerberg):

title = {What you really need to know about the Internet: From {Gutenberg} to {Zuckerberg}},. See https://tex.stackexchange.com/q/10772/35864. Do not blindly protect all words in the title or the entire title if you don't want sentence case. Instead choose a different style that leaves titles in title case. – moewe Apr 05 '18 at 09:14