"The map markers won't point exactly to the postcode, but to a close random position to protect your identity."
When you enter the postcode I get the geolocation for that. Then I set the marker to a random position nearby, I think it's a few hundred meters away. So if the postcode geolocation is a few hundred meters from your home and the random position makes it point right to the house, then you're f*ckd.
If that does happen, change the postcode to something else, and then change it back. That will do the randomization again so it should point somewhere else.