Most serious commenatators have stated that Hezbollah do not have scuds, it's just another scare campaign by Israel to legitimize an attack Lebanon again.
They are large, not easily hidden and would make a very easy target for Israeli jets which fly over Lebanon constantly. I presume they get lot's of data from these flights plus any satellite up there from which any data would be monitored constantly.
http://www.nowlebanon.com/NewsArchiv...aspx?ID=166086
http://www.reuters.com/article/idUSTRE63H1RQ20100418
BEIRUT: Long-range Scud missiles, which Israel has accused Syria of sending to Lebanon’s Hizbullah, seem unlikely weapons of choice for a nimble guerrilla outfit.
“Hizbullah needs to float like butterflies, sting like bees. They don’t need something that lumbers along like an ox,” British defense analyst Charles Heyman said.
About 11 meters (36 feet) long, a Scud usually is fired from a huge wheeled transporter-erector-launcher, backed by support vehicles. A launch needs 45 minutes to prepare, Beaver said.One Israeli official said Hezbollah had received only the missiles to place in "improvised silos," not the launcher and tow truck. It was not immediately clear how the guerrillas could launch the missile without its companion equipment.
Uzi Rubin, a founder of Israel's Arrow anti-missile programme and now a private consultant to the Defense Ministry, voiced surprise at reports of Scuds reaching Hezbollah.
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This is a nonsense move. What do they need Scuds for?" he asked.
"They already have the (Iranian-made) Fateh-110, which has a similar range and, being a solid-fuel rocket, is far less cumbersome. Okay, so Scuds weigh a tone while the Fateh-110 is half a metric tone. Nothing to stop them firing two Fateh-110s."
Syria has said Israel's "fabrications" about Scud deliveries were intended to "raise tension further in the region and to create an atmosphere for probably Israeli aggression."