Seems like a third world country trying to act relevent by policing it's technology, without any real clue of what it's doing. Basically aping what first world countries are examining and making a ruling so they can show that they can. Sad but true.
That point which some people will probably not like aside, let's examine this.
1. Despite what a lot of Americans believe the entire world has substantially less freedom than the US to begin with, including most "enlightened" first world nations that are compared to the US favorably without much actual information. Claiming that certain things curtail a freedom of speech doesn't make much sense unless a given people has the same kind of fundemental guarantee that the US has (where it was one of our founding principles). This also incidently makes it easier for many nations to pass sweeping laws of this sort, since they don't have to worry about the same issues to the same degree. Most countries with free speech laws don't have them enshrined as a basic, fundemental principle, the way the US does.
That point aside, the law that will prevent trolling is more or less irrelevent. Unless their definition of slander/libel works far differantly in practice than that of the US, your dealing with what is fundementally an unenforcable law, no matter what sentence is attached to it.
The reason for this is simple, you need to prove that the guy engaged in slander or libel is making something up, and had no reason to believe what they were saying was true. If some guy can justify why he thought such a thing it's more or less a non-issue. A simple rumor can be used as a defense, unless you can prove the guy being prosecuted started it, or even then have to prove that he had no logical reason to believe what he did. Companies and individuals who do contreversial or unpopular things and keep the truth close to themselves effectively make themselves victims. All of this (believe it or not) is a big part of why you don't see slander and libel suits being thrown around left and right.
Basically what the Phillipines is doing is threatening a 12 year prison sentence as a deterrant, and reinforcing that such laws apply to computers, they still apparently have to prove libel, but can use someone doing it with a computer as an aggravating circumstance for a more severe sentence. In the end trying to actually enforce this would probably bankrupt their court system. Journalists and those who act as sources actually have more to worry about here than your typical troll.
2. When it comes to the entire "cybersex" thing I think it's doomed. I also think a lot of people are not thinking this through, it seems to me like a classic back door measure from the way it's defined. It's morality law.
The way this reads they could pretty much outlaw any porn movie that used digital editing or camera equipment (working through computers/hard drives/etc...) and indeed any movie with adult material. I think THAT is the intent more than anything here, despite how the law appears.
The Phillipines having something of a reputation as being one of those sexual wild wests despite any domestic laws on the subject. It's a place you can order custom "art movies" from as well as a common destination for sexual tourists who want to solicit prostitutes, or bring children outside of their country to have sex, or whatever else. Deserved or not, it's up there with a few other countries/regions. This could be intended to curtail this entire area of behavior.
As far as "Cam Girls" go,it can be complicated. You do indeed have virtual peep shows where instead of a booth girls do things in front of a web cam for an audience. However when the term "Cam Girl" as opposed to "Cam Whore" is used semi-officially a differant meaning tends to arise, even if the common vernacular makes them interchangable.
Your typical Cam Girl is a predator who hangs out on sites frequented by nerds and lonely guys. They act friendly through chat, eventually arrange a "face to face" via Camera, and then gradually start giving sob stories, as a way of soliciting money, gifts, and other things. Sometimes this can overlap with flirting or people showing off their naughty bits and such, but for the most part it refers to a differant kind of con. This kind of thing is a big part of why there is so much distrust of "geek and gamer girls" especially those that are attractive. When caught some of these girls wind up on sites like "Encyclopedia Dramatica" in one form or another by way of payback.
At any rate, I'd imagine if the target is cam girls (which this law won't really work for, for reasons I probably don't have to explain, among them the nessecity of sexual material) it's because you had a lot of guys getting POed about being scammed and complaining about it. Basically if some girl begs stuff off of you after forming a connection, you comply, and then find out she does nothing but sit around all day begging gifts off of a circle of differant people, perhaps with differant stories, your going to be rather upset.
I seem to remember years ago there was a failed attempt to legislate away "gift lists" on sites like Amazon.com and other virtual merchants, as they were heavily exploited by cam-girls as a way of people sending them things behind a veil of relative anonimity.
The big differance is your typical cam-girl is more of a con-artist, or cyberspace grifter, preying on vulnerable and lonely guys. Sex might not be involved. Cam-whores are self explanitory. The two can overlap, but that's not a given. In cases where something overlaps you might find an underage girl who feels safe on the internet (as an example) showing off her goods in exchange for presents. In many cases I've heard alleged "cyber molestors", are lonely people with a lack of willpower, with it being the girls who initiate such things feeling safe behind the internet, and enjoying the presents they get, and then claiming victimization when they are caught. Of course there are millions of variations, I'm sure we've all heard the stories in all directions.