Two examples of poor security measures:

In fact, everything that interfaces with the Internet can get hacked. In any case, there are a few things you can do to shield yourself and your information from an attack. A decent principle to pursue is never open connections except if you are 100% certain of where they originated from. One of the least demanding courses for programmers to download vindictive code onto injured individual PCs is by sending messages with infection loaded documents. 

In the meantime, some of Silicon Valley’s most noticeable figures are fanning the fire. Most quite, Elon Musk erased his organizations’ Facebook pages, and WhatsApp organizer Brian Acton freely urged clients to erase their Facebook profiles. This means records lows for client trust in Facebook. An ongoing Reuters survey uncovered that individuals are losing trust in Facebook and its practices.

I completely agree that one should always log out of an application properly. To support the point of hackers can post material, I believe they use some process like SQL Injection. I also agree that social engineering and social network sites are very common places where due to lack of security measures attacks happen more often.