Everyone will use EM to download all kinds of things. Downloading requires searching, and others sometimes use your computer. You don't want people to see the keywords in the search history, so take a look at the following removal methods, some of which are from pletion= 1 and change 1 to 0, so that emule will never save the search history again.
BTW: Modifying useautocompletion=0 will also stop em from saving the following three historical records.
AC_BootstrapIPs.dat
IP address and port of boot program in Kad.
AC_IPFilterUpdateURLs.dat
Update the URL of IPFilter.
AC_ServerMetURLs.dat
Update the URL of the server list.