Belive me they do. I know the person who used to be "official LH lurker" on Miles & More. She did fantastic and based on her relationship with FT and LH, lots of stuff has been achieved. Not always what FTers would want but often a lot. During the volcano crisis earlier this year, she was first point of contact between LH and most of the FT and this was officially sanctioned by LH. We often knew operational decisions before M&M and LH call centre staff, because she could post them as soon as she left meetings. She was even tweeting directly from those meetings.

So, yes the do monitor. Not all of them, but they do. And that's the reason why I am not big fan of posts where people clearly offer or seek something that is not exactly "kosher" or can sometimes be cosidered as illegal, fraudulent and/or inappropriate. These compaies will notice and will make sure that it will stop.