diff --git a/src/dolphinviewcontainer.cpp b/src/dolphinviewcontainer.cpp
--- a/src/dolphinviewcontainer.cpp
+++ b/src/dolphinviewcontainer.cpp
@@ -44,6 +44,7 @@
 #include <QDropEvent>
 #include <QLoggingCategory>
 #include <QMimeData>
+#include <QProcessEnvironment>
 #include <QTimer>
 #include <QUrl>
 #include <QVBoxLayout>
@@ -108,6 +109,28 @@
     m_messageWidget->setCloseButtonVisible(true);
     m_messageWidget->hide();
 
+#ifndef Q_OS_WIN
+    QProcessEnvironment system_env = QProcessEnvironment::systemEnvironment();
+
+    // If running as root, show a big scary warning
+    if (system_env.value("USER") == QStringLiteral("root") &&
+        system_env.value("SUDO_USER") == QStringLiteral("root")) {
+        showErrorMessage(i18n("Running Dolphin as root can be dangerous. Please be careful."));
+    }
+    // If running with sudo, inform the user that this isn't necessary
+    else if (system_env.value("USER") == QStringLiteral("root") &&
+        ! system_env.value("SUDO_USER").isEmpty()) {
+        /* TODO: change this message to instead encourage people to run with normal
+         * permissions for their system-file-and-other-user-file-management needs
+         * once PolicyKit support is added to KIO and enabled:
+         * - https://bugs.kde.org/show_bug.cgi?id=179678
+         * - https://phabricator.kde.org/T6561
+         * - https://phabricator.kde.org/T8075
+         */
+        showErrorMessage(i18n("Running Dolphin using `sudo` can be dangerous and may expose you to security risks."));
+    }
+#endif
+
     m_view = new DolphinView(url, this);
     connect(m_view, &DolphinView::urlChanged,
             m_urlNavigator, &KUrlNavigator::setLocationUrl);
diff --git a/src/main.cpp b/src/main.cpp
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -35,21 +35,8 @@
 #include <QApplication>
 #include <QCommandLineParser>
 
-#ifndef Q_OS_WIN
-#include <unistd.h>
-#endif
-#include <iostream>
-
 extern "C" Q_DECL_EXPORT int kdemain(int argc, char **argv)
 {
-#ifndef Q_OS_WIN
-    // Check whether we are running as root
-    if (getuid() == 0) {
-        std::cout << "Executing Dolphin as root is not possible." << std::endl;
-        return EXIT_FAILURE;
-    }
-#endif
-
     QApplication app(argc, argv);
     app.setAttribute(Qt::AA_UseHighDpiPixmaps, true);
     app.setWindowIcon(QIcon::fromTheme(QStringLiteral("system-file-manager"), app.windowIcon()));