Looks like a debug log was simply left in the source. Many URIs are plain logged into ~/.xsession-errors as KUrl lines, whenever a tab creation occurs or whenever user switch tabs, or uses the search box in Konq. Also applies to Dolphin at least.

Reproducible: Always

Steps to Reproduce:
1. Start Konqueror or Dolphin
2. Search anything using Konq search box, or open any URL in any tab, and/or switch tabs
3. grep KUrl ~/.xsession-errors
Actual Results:  
~/.xsession-errors hold traces for many visited URLs, for each tab creation or even tab switch, it seems

Expected Results:  
~/.xsession-errors holds no such traces

kde-baseapps-4.10.4-1.fc19.x86_64
  as found in Fedora 19 Live KDE (Final RC3/GOLD)

Examples (anonymized a bit):
KUrl("http://start.fedoraproject.org/") KUrl("http://start.fedoraproject.org/") 
KUrl("https://mail.google.com/") KUrl("https://mail.google.com/") 
KUrl("http://www.example.com/article/2013/07/02/9999999-some-press-article.html") KUrl("https://news.google.com/")
KUrl("https://www.example.net/xxxxxxxx/dependiente/of-deadbeefcafedeadbeefcafedeadbeefcafe") KUrl("") 
KUrl("file:///home/liveuser") KUrl("file:///home/liveuser") 
KUrl("fish://USER@IP.IP.IP.IP:PORT/") KUrl("")