I used a bunch of them a while back in a house where the omnipotent and omniscient "MASTER ELECTRICIAN" had not only run the data wires along with the Romex, but had actually tie-wrapped them all together. The customer's computers and whole-house audio system wouldn't work (shock!) I couldn't re-run them, because it was a finished house, so I used those splice boxes on a dozen or so re-routed Cat5e cables. Everything works, and I haven't heard any complaints since then.
