The Thuraya satellite being jammed is Thuraya 2 (2003-026A), a geosynchronous satellite located at 44 degrees East, over East Africa:
I have imaged this satellite several times, as it's position is close to that of USA 202/Mentor 4 (09-001A). Thuraya 2 is the upper of the two objects in below image, which I shot at 8 December 2010 using the Carl Zeiss Jena Sonnar MC 2.8/180mm:
I wonder whether the jamming is not only aimed at Thuraya 2, but perhaps also at the nearby Mentor. The latter is a SIGINT satellite, and jamming it would hamper US intelligence gathering on what is currently going on within Libya (and northern Africa and the Arabian peninsula in general). It is not clear to me however whether the jamming is "local" on the Thuraya downlink over Libya, or actively aimed (in an "uplink" sense) at the satellite.
Libya was accused of jamming Thuraya 2 earlier in 2006 (see here and here).