For purposes of the following discussion, please assume that there is a non-international armed conflict ongoing in Syria. Thus, international humanitarian law is operative.
Today, Syrian rebels attacked a pro-Assad TVstation, killing seven people including journalists and security guards. The pro-Assad TV station attacked, Ikhbariya, is apparently not a state-owned enterprise. Instead it is a privately owned media with a pro-government view point. Although not necessarily relevant, the ownership status of the station may be an important indicator of whether the station itself was a legitimate target.
The question of whether the station itself was a legitimate target is answered by whether it was a military objective. To be a military objective, an object must by its “nature, purpose, or use make an effective contribution to military action” and the destruction of that object “must offer a definite military advantage” at the time of the attack (See, e.g., Additional Protocol I). Those objects not meeting this definition—civilian objects—are not legitimate targets. Clear military objectives are things like anti-aircraft batteries, general headquarters, or tanks. Objectives that may or may not make “an effective contribution to military action” at a given moment include things like power stations that service civilian electrical grids or trains.
Television and radio stations sometimes fall into the category of objects that, although generally civilian in nature, also serve a military purpose, making them at times legitimate targets of attack. For example, during the NATO bombing of Serbia in 1999, NATO targeted a Serbian Radio and TV transmitter, killing several civilians, because it was integral to Serbian Command, Control, and Communications networks. The Office of the Prosecutor for the ICTY released a report on that and several other NATO attacks accused by Serbia of violating international humanitarian law. Said the Office of the Prosecutor:
[T]he attack appears to have been justified by NATO as part of a more general attack aimed at disrupting the FRY Command, Control and Communications network, the nerve centre and apparatus that keeps Milosevic in power, and also as an attempt to dismantle the FRY propaganda machinery. Insofar as the attack actually was aimed at disrupting the communications network, it was legally acceptable.
If, however, the attack was made because equal time was not provided for Western news broadcasts, that is, because the station was part of the propaganda machinery, the legal basis was more debatable. Disrupting government propaganda may help to undermine the morale of the population and the armed forces, but justifying an attack on a civilian facility on such grounds alone may not meet the "effective contribution to military action" and "definite military advantage" criteria required by the Additional Protocols .... The ICRC Commentary on the Additional Protocols interprets the expression "definite military advantage anticipated" to exclude "an attack which only offers potential or indeterminate advantages" and interprets the expression "concrete and direct" as intended to show that the advantage concerned should be substantial and relatively close rather than hardly perceptible and likely to appear only in the long term (ICRC Commentary on the Additional Protocols of 8 June 1977, para. 2209). While stopping such propaganda may serve to demoralize the Yugoslav population and undermine the government’s political support, it is unlikely that either of these purposes would offer the "concrete and direct" military advantage necessary to make them a legitimate military objective.
Notice that the Office of the Prosecutor took pains to discount the notion that a broadcast facility used strictly for the transmission of propaganda (or news) is a legitimate target, whatever impact it may have on the morale of opposition forces. However, the report also indicated that the use of a transmission facility, as in Rwanda, to incite violence may render that transmission facility a legitimate target.
The private nature of the Syrian television station attacked today means it is unlikely to comprise an element of Syrian C3 today. This is not to say it could not be used for C3 purposes in an ad hoc manner in the future if, say, regular Syrian C3 were degraded by a bombing campaign. However, the military objective test demands we examine the circumstance as they exist not as they could exist.
If that station does not form part of Syrian C3 then it is likely not a military objective. That said, if the station was being used by irregular pro-Assad forces to incite violence at the moment it was attacked, then it may have been a legitimate target. This reasoning seems to have guided the NATO bombing of a Libyan satellite transmitter last year but it is not without its detractors.
And what of the journalists? The journalists killed in today’s attack were almost certainly innocent civilians—as opposed to civilians directly participating in hostilities. Although IHL’s prohibition on attacking innocent civilians is strict, when civilians are killed as an incident to an attack on a military objective their killing does not violate IHL so long as their deaths were not in excess of the military advantage to be gained by destroying the military objective. Obviously, if the TV station was not a military objective in the first place then the killing of these journalists would in fact qualify as a war crime.