We see these ads on the streets, and most Qataris are perplexed by them...

They seem mostly unrelated to much of what happens here, LP talks about the sponsorship system, but the website linked above says that human trafficking is "recruiting or transporting or sheltering or receiving under threat or exploitation or force or other kinds of compulsion or kidnapping or deception or trickery or misuse of authority or exploitation of the weakness or giving/taking benefits to attain the approval of person, for the purposes of exploitation for work such as prostitution or sexual exploitation or forced labor or drudgery or making slave or similar activities of slavery or bondage or removing organs." (from one of "Palermo Protocols").

Then this doesn't seem to apply to the sponsorship system.