In the year 312, the story goes, Constantine looked into the midday sun and saw a cross in the sky, with the words "By this sign, conquer".  His army placed the cross onto their armor and won the Battle of Milvius Bridge against Maxentius, thereby winning the Roman civil war and making himself emperor.   He and the empire became Christian and the cross moved to the forefront of Christian symbols, although the magic did not last.  In 410 pagan Visigoths defeated Rome and pillaged the city.  But the cross has endured.  At least, until now.
The US Supreme Court has overruled a lower court decision to order the removal of a cross in the Mojave Desert, which is a public park.  The cross was apparently meant as a memorial for World War One but is simply two crossed pipes on a hilltop.  The majority decision used the reasoning that the cross is universal, not Christian:

A Latin cross is not merely a reaffirmation of Christian beliefs. It is a symbol often used to honor and respect those whose heroic acts, notable contributions and patient striving help secure an honored place in history for this nation and its people

Here in San Diego we have the cross on Mount Soledad.  A cross (there was a series of them) has stood near the summit for decades, usually known as the Mount Soledad Easter Cross since large services were held there on Easter.  Due to controversy, in the 1990's the site became a Korean War memorial, and the city sold the land to the Mount Soledad Memorial Association.  But the legal wrangling has continued as the conversion to a war memorial and the sale have come under scrutiny.  A 2008 judgement struck a note similar to the more recent ruling:

“The memorial is not designed for worship services, and there is no evidence the cross, which is surrounded by a tall fence and not approachable by visitors, is — or is intended to be — the object of religious devotion,” Judge Burns wrote, adding, “The primary effect of the Mount Soledad memorial is patriotic and nationalistic.”

 So,  is the cross now like Santa Claus and the Easter Bunny, not really religious?  (Hint: no.)