? := a tendency on the part of an individual or group toward excessive or irrational suspiciousness and distrustfulness ...
The only way to get this to interfere with the system is:
$ su -
# cd /usr/src/rpm/SOURCES
# tar -xf kdebase-3.5.10.tar.bz2
# cd kdebase-3.5.10
# (also need to happen to have X sources installed)
# make install
That ain't gonna happen by accident
Seriously, if the src.rpm wasn't meant to be installed in /usr/src then why does the rpm command install it there ?