Summing up how American media works:
I can speak for American media. There is no real restriction, it's protected in the first amendment. Of course it's up to the indiviual working within the media how they handle that freedom, some people take advantage of that and write things or express things that defames a person, that, they can get in trouble for because there are laws against that. People like that generally lose their job soon after. The law protects civilians from the media unless they've commited a crime and the media here can't out rightly say someone has done something until they've been convicted, they can't even hint it. There are laws that protect public figures and celebrities but if they claim that the media had ruin their image in any way they have to be able to prove that what's said or printed isn't true, which a lot of the time is hard to do that's why they don't bother to sue the media, it's hard to win cases like these but not impossible.
Of course don't get the news confused with tabloids, that's not even on the same ethical level. Tabloids know their rights and they know they can get away with a lot of the garabe they print. News is more responsible (real news, there are fake news on TV that's for entertainment purposes but some people seem to think it's real) with what they print because their company's name and integrity is on the line. If the public can't count on you to give them correct information they'll go else where. You'll have the handful of of reporters who go and so something stupid like make up a story, when it's a reputable reporter no one is going to assume that the story is made up. It's happened a couple of times, one with a New York Times reporter, obviously that person was fired (stupid move because a lot of reporters would give anything to writer for the New York Times).
As for free speech, Thailand is it's own country they can do whatever they want. In America free speech also falls under the first amendment. It protects citizens right to speak out against the government if they choose to, without any fear of persecution. It's good to question authority, if you follow blindly and take their word on everything, eventually someone's going to take advantage of that.
Anyway, sorry I_love_sam, for hijacking your thread. Lets get back to the topic.