Meet the Spartans

The film opens with a Spartan elder inspecting three babies. The first, an ugly, talking baby ogre (Shrek the Third), is abandoned to die for its deformity; while the second, who is Vietnamese, is adopted by Brad Pitt and Angelina Jolie. The third, Leonidas, is accepted as a Spartan for his already-present muscular physique and prepared for kinghood through brutal training. An adult Leonidas (Sean Maguire) is cast out into the wild, survives the harsh winter, and hunts down a gangsta penguin (Happy Feet). Returning a king for his inauguration wearing a penguin skin hat, Leonidas sees Margo (Carmen Electra) erotically dancing and asks her to marry him, to which she responds by giving him the combination to her chastity belt.
Years later, Leonidas is training his son when Captain (Kevin Sorbo) informs him that a Persian messenger has arrived. Accompanied by the Spartan politician Traitoro, the messenger presents Xerxes' demands for Sparta's submission. After growing angry with both the messenger's disrespect and finding him making out with his wife, Leonidas kicks him into the "pit of death". Despite Traitoro's advice that the messenger's guards are now needed to convey the actual message, Leonidas kicks them in as well, along with several other people he simply dislikes. Resolving to face the Persians, Leonidas visits the prophets and gives them medicines such as Neutrogena as their prize for their consultation. They advise him that he should consult the Oracle for any advice. The Oracle, Ugly Betty, reveals that Leonidas will die should he go to war.
After reaching a decision while spending the night with his wife, Leonidas meets the soldiers assembled for his departure to Thermopylae, and finds that only thirteen were accepted in the army due to stringent requirements. Among them are Captain, his son Sonio, and a slightly unfit Spartan named Dilio. Once at the Hot Gates, they encounter a deformed Paris Hilton (also played by Parker), who tells Leonidas and the Captain about a secret goat path above the Hot Gates that Xerxes could use to outflank the Spartans. When she asks to be made a Spartan soldier, Leonidas rejects her as unqualified due to her inability to use a spear correctly. Leonidas and his platoon soon face off with Xerxes' messenger and his Immortals, beating them in a dance contest before driving them off a cliff. Xerxes (Ken Davitian), impressed, personally approaches Leonidas and attempts to bribe him with a trip to the Palms Hotel and Casino. Leonidas declines, and the Spartans face the Persian army in a "Yo Momma" fight, which the Spartans win, but Dilio has his eyes scratched out and wanders away.
Hilton decides to betray the Spartans and reveals the location of the goat path to Xerxes in return for various gifts and for having her deformed hump removed. Xerxes meets the twelve remaining Spartans and the war begins. Meanwhile, back in Sparta, Queen Margo has several confrontations with Traitoro, as he is the vital vote in sending more troops to assist her husband. Following her address to the Council, Traitoro publicly betrays the Queen. The Queen then battles Traitoro in a parody of Spider Man 3 and defeats him using a dust buster. With Traitoro's deceit exposed, the council is united with the queen.
At the Battle of Thermopylae, the Persians introduce their secret weapons, Ghost Rider and Rocky Balboa, who kills Sonio with a decapitating uppercut. Captain avenges him with Botox poisoning before being struck down by Xerxes. Leonidas pursues Xerxes and plays Grand Theft Auto. Managing to find the "Transformer Cube", Xerxes uses it in a car to become Xerxestron and shows off his powers to access the "Leave Britney Alone!" video on YouTube. However, Xerxestron accidentally trips on his extension cord and falls on Leonidas and the surviving Spartans, apparently killing them. The blind Dilio eventually returns to Sparta to tell of Leonidas' final moments. A year later, Dilio leads a larger Spartan force to defeat the Persians, but the blind warrior ends up going the wrong way. They end up in Malibu, where they knock Lindsay Lohan down as she is leaving rehab again.

Question: What video was on YouTube?
Answer: "Leave Britney Alone!"