(in the US) there aren't any specific laws that "encourage" such behavior, but you may be referring to so-clled "good samaritan laws" which shield people wishing to give such aid, from being sued by the very people they are intending to help.
battery
No adult can hold another adult against their will. In most states of the US that would be unlawful imprisonment.
Another name for it is wave interference.
They each have different beliefs that often contradict one another, however, they have a commonality in that they encourage nonviolence against one another.
assault
This depends on the laws of the country in which you reside. Generally it is against the law to be married to more then one person at a time.
The word illegal means the same as unlawful. Along with this, unjust works. If you're looking for moral based, unethical.
Constructive interference can be a confusing concept when called interference. It is wave interference that is moving in phase with another wave. This causes the waves to for a resultant wave with a greater amplitude. Destructive interference is wave interference that is moving out of phase with another wave. These waves form a resultant wave of lower amplitude.
Another word for squatter would be unlawful resident or trespasser.
interference
Cacellation
destructive interference