Can the take-over of humans by an extraterrestrial consciousness be used to carry out acts of aggression? Will that override the morals of the person to cause something out of character to be done?

This indeed can happen and is done routinely. This is an interesting and most alarming extension of their capability that follows naturally from considering their ability to enter the mind and impinge on the thoughts of an individual. It is not just within the subconscious—they can create a state of presence within the mind that, in effect, takes over and pushes the conscious self to one side and then command the body to carry out direct actions of movement and speech. So this, in effect, turns a person into an automaton for an interval, during which time anything can happen whether or not it is in keeping with their personal habits, or characteristics, or even moral character. We understand this is quite distressing and stretches the limits of credulity to near breaking point, but if you look at the world and how it operates, this does fit perfectly into the scheme of things and will go a long way to explain inexplicable behavior that is out of character, or in keeping with character, but leaves the person with no recollection of a period of time during which tragic events take place at their doing. This is usually dismissed by the authorities as a form of cover-up and a lie when, in fact, it is usually truthful because it represents an extraterrestrial incursion to cause mischief and leave no understandable traces. So the secret keeps itself because the person affected will simply not be believed. There will be eyewitnesses to a crime, for example, and often a video record of their presence carrying out heinous acts. There may well be words exchanged in keeping with the seeming bizarre and twisted actions underway and may well match internal ideology or delusional thinking of some kind. So often people will be primed with the inclination to take matters into their own hands to right a wrong or champion a cause, even one depending on twisted logic. Once primed, they can simply be switched off and made to carry out a plan of attack that was not thought about in advance in detail or may have been implanted as a suggestion within the mind for them to ponder and think about the pros and cons. This doubly indicts the person even in their own mind, when they seem to wake up in the aftermath of such an event, if they indeed survive it, with no recollection of the intervening interval, but also know what took place was in keeping with prior thoughts of theirs and so they will naturally blame themselves along with the rest of society.