This is an interesting assertion. Have you every tried this? Let's take a look at the from a theoretical perspective, to see if this makes sense.
If you assume an output level from the DVR of 20 dBmV (or about -27 dBm), loss in the cable to the antenna of 10 dB, and loss in the splitters of about 10 dB, you get -47 dBm at the antenna.
If you then assume combined (transmit & receive) antenna gains of 6 dB, receiver sensitivity of -90 dBm (which requires a noise figure of about 17 dB--with a good preamp the sensitivity could ve -104 dBm or lower), and feedline loss at the neighbor of another 10 dB (but no feeline loss to the neighbor with the preamp), you could withstand 39 dB off loss to the neighbor (or 63 dB to a neighbor with a preamp).
The Free Space Loss Calculator (
Free Space Loss Calculator) shows that at channel 3, 39 dB of loss is about 0.02 miles, or about 100 feet. For 63 dB of allowable loss, it's about 0.34 mile. At TV channel 60, the distances are 10 and 150 feet.
So if you are using TV channel 60, and your neighbors don't have preamps on their antennas, no one is going to see anything. Or if you all have directional antennas, and they are never pointed at one another, you might be okay (depending on the antenna patterns). But if your neighbors have good preamps, and you are using a signal at channel 3, people as far as 1/3 of a mile could see what you are watching (or somewhat less, depending on the antennas used, and how they are pointed).