Just in case, we'll take your guns...

Cops allowed to seize firearms before crime is committed
Excerpt:

A new report to the Connecticut state legislature shows police have used the state's unique gun seizure law to confiscate more than 1,700 firearms from citizens based on suspicion that the gun owners might harm themselves or others.
The state's law permits police to seek a warrant for seizing a citizen's guns based on suspicion of the gun owner's intentions, before any act of violence or lawbreaking is actually committed.
Link to article

Prior to the seizure of one man’s firearms, police cited in their application the man’s “extensive self-protection measures” that were installed on his property, “including alarms, cameras and spotlights.”

Sum it up with this:
Having a home alarm system, security cameras and floodlights is a cause for police to confiscate your guns on suspicion.
A neighbor who doesn't like you can call the police to have them come and take your guns.