These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Designated Villain: Detractors claim that the DHS is this, stating that they're merely doing their jobs to protect the country.
Gary Stu: Marcus, arguably. A little less in the sequel, though, where he is much more emotionally vulnerable and self-deprecating.
Unfortunate Implications: Are we supposed to think Charlie's cheap ad-supported phone proves he's a loser, rather than that he can't afford anything better?
Wangst: In the sequel to Little Brother, Homeland, Marcus occasionally lapses into this, though to be fair, he is under a lot of pressure.
What an Idiot: Quite a few of Marcus's problems are self-inflicted. One major example is that he would have gotten out of his interrogation sooner if he had just let Carrie look at his phone knowing full-well that there was nothing on it that would send him to prison. Then there was when he tampered with the new security system just to make a point to his father, whom had no problem with the DHS's actions. This led to the DHS tightening security even harder.