First, let me apologise for my ignorance...almost all of my work is with "power" circuits.
I do pull a fair amount of Cat-5 for my customers, even make terminations at times. I have always bee careful with pulling force, the use of D-rings, etc.
On another job, the customer hired someone else to run the phone/data wire. The firm he hired specialises in this work, and is not the smallest or newest kid on the block.
So what do I see, but the other crew stapling the Cat-5 to the wood beams every few feet- just like the phone company used to do in homes.
I was taught that doing so would ruin the Cat-5.
Yet, I can't believe that this guy would have gotten away with this, for as long as he has, if there was a problem doing so. (To replace a line at this place would entail LOTS of demo- bldg uses 'wood I-beams')
So tell me- am I overly cautious- or is this guy flirting with disaster?