All alone, or in two's,
The ones who really love you
Walk up and down outside the wall.
Some hand in hand
And some gathered together in bands.
The bleeding hearts and artists
Make their stand.

And when they've given you their all
Some stagger and fall, after all it's not easy
Banging your heart against some mad bugger's wall.

 

Outside the Wall (Pink Floyd, Waters 1977)

"I oppose the building of the wall and its construction will stop," al-Maliki said during a joint news conference with the Secretary-General of the Arab League Amr Moussa in Cairo. "There are other methods to protect neighborhoods. This wall reminds us of other walls"

There is little doubt as to which wall al-Maliki was refferencing. Israel has continued it's construction of it's concrete baricade despite International and U.N condemnation.

UPDATED:   The construction of a three-mile wall around a Sunni neighbourhood in Baghdad continued Monday, the military  spokesman for the Iraqi government said, despite Premier Nuri al-Maliki's opposition to the plan.

In a recent report, the UN stated that:

"...it is difficult to overstate the humanitarian impact of the Barrier. The route inside the West Bank severs communities, people’s access to services, livelihoods and religious and cultural amenities. In addition, plans for the Barrier’s exact route and crossing points through it are often not fully revealed until days before construction commences. This has led to considerable anxiety amongst Palestinians about how their future lives will be impacted...The land between the Barrier and the Green Line constitutes some of the most fertile in the West Bank. It is currently the home for 49,400 West Bank Palestinians living in 38 villages and towns" ^[30]

And from Wikipedia there is this...

As of May 2004, the fence construction had already uprooted an estimated 102,320 Palestinian olive and citrus trees, demolished 75 acres (0.3 km²) of greenhouses and 23 miles (37 km) of irrigation pipes. At that point, it rested on 15,000 dunums (3,705 acres or 15 km²) of confiscated land, only meters away from a number of small villages, or hamlets. In early 2003, in order to move a section of the barrier to the Green Line, a ramshackle mall of 63 shops straddling that line into Israel was demolished by the IDF in the village of Nazlat Issa .^[42][43][44] In August of that year, an additional 115 shops/stalls (an important source of income for several communities) and five to seven homes were also demolished there.^[45][46] The Israeli Government has promised that trees affected by the construction will be replanted.^[47] According to the United Nations Relief and Works Agency (UNRWA), 15 communities were to be directly affected, numbering approximately 138,593 Palestinians, including 13,450 refugee families, or 67,250 individuals. In addition to loss of land, in the city of Qalqilyah one-third of the city's water wells lie on the other side of the barrier. The Israeli Supreme Court notes the Israeli government's rejection of accusations of a de facto annexation of these wells, stating that "the construction of the fence does not affect the implementation of the water agreements determined in the (interim) agreement".^[1]

Some other Walls of note throughout history - Not a very successfull bunch.

• Anastasian Wall This wall had only a limited effectiveness, and the barbarians penetrated it many times, because the fortification's length made it difficult to defend the wall completely by a limited garrison, and also because the wall was not sufficient strong due to its construction in hurry.

  The wall fell into ruin after it was abandoned in the 7th century because of the difficulty of keeping it manned and repaired. Over the centuries, the stone of more than half of the total length was reused in other local buildings. It is best preserved in the woodlands of the northern sector.

• Antonine Wall This wall was abandoned after only twenty years, when the Roman legions withdrew to Hadrian's Wall in 164
• Hadrian's Wall on the English-Scotland border, UK
• Jericho walls
• Jerusalem's Old City walls in Jerusalem, Israel
• Kremlin Wall - Originaly built of Oak, then promptly burnt down. Rebuilt of limestone, Moscow was again promptly invaded, although the wall suffered little damage.
• Serpent's Wall, the ancient walls in Ukraine
• Wansdyke, in western England, UK
• Offa's Dyke between England and Wales, UK
• Servian Wall, in Rome
• Wall of Phaleron, outside Athens, Greece
• London Wall in England, UK
• York city walls in England, UK
• Chester city walls in England, UK
• Long Walls linking the port of Piraeus to Athens, Greece
• Roman Walls of Lugo, Spain
• Themistoclean Walls, outside Athens, Greece
• Trajan's Wall, in Dobruja, Romania
• Western Wall in Jerusalem (also called the Wailing Wall, Kotel HaMa'aravi, and Al-Buraq Wall)
• Great Wall of Gorgan in Iran
• Intramuros Walls, Manila, Philippines
• Great Wall of China, China
• Cheolli Jangseong China (for the Goguryeo one) and North Korea ( for theGoryeo one)