Insider Threat - Who Can You Trust?

In our era of being always "on", where everything we do is somehow connected to the Internet, every single one of us has the ability to cause harm to others at the touch of our fingers through the glass of a screen. Whether driven by vengeance, money, retaliation, the need for notoriety, or sheer incompetence, the Internet gives all of us an opportunity to attack others, leak juicy information, spread hateful gossip, and tear apart trusted relationships. In cybersecurity, we call this type of threat ?Insider Threat?.
The Vengeant Partner
Perhaps you've had an argument, or your partner feels neglected and wronged. Your partner controls your cell phone's family plan. Will they lock you out of your phone and all your apps just because they can?
The Greedy Swindler
You hear about a great investment opportunity through an online friend of yours. Your friend insists the investment is reputable. You've been virtual friends for several months now, you've even had virtual happy hours together, and have a vacation planned next month, so you trust them. You have even let them into your social circle. You decide, "hey, why not dabble in this investment?" Things are going well, you are making money. You decide to invest even more - this might just pay for the vacation you are about to take. Is this person to be trusted? Are you being swindled by your "close" friend?
The Angry Former Employee
They deserve a bonus and raise - they have had access to the source code behind your company's business applications. The company is doing so well, they want their piece of the pie, but do not get the raise they "deserve". In retaliation, they add several lines of bad code into the business application making it completely unusable, and on top of that, leak intellectual property to your competitor. Could you have prevented this? Did you fail to see the warning signs?
The Attention-Seeking Frenemy
You are in the same neighborhood and have many mutual FaceBook friends. You have so much in common, the two of you start your own FB group and give each other access to each other's accounts. The FB group ends up taking too much time to maintain, so you forget about it. Months pass and you are bored. Against your best judgement, you post a little too much personal information about yourself on FB. Your post gets a lot of attention and likes. You don't know this, but all your attention upsets your "friend" who you haven't seen for months. Before you know it, you have lost access to your own FB account where you have all your photos and personal information. Did your "friend" intentionally do this to you? How can you regain access to your FB?
The Incompetent Service Provider
You install a new video camera security system to protect yourself from all the burglaries happening in your neighborhood. As a bonus, the service provider gives you extra cameras which you put inside your home so you can monitor your kids from an app on your phone. Turns out, the service provider does not screen its employees and hires incompetent staff. Through incompetence, your video footage can be streamed online by anyone through one click. Since the service provider keeps a one-year history of your video, even if you discontinue service, your videos are still in their hands. Do you know your privacy rights? What can you do?
Are you prepared to protect yourself from Insider Threat?