Back in the '80s, there was a big charity event called Hands Across America. The idea was to form a human chain from coast to coast for about 15 on a Sunday in May and have a large chunk of America literally and symbolically united. The trick is, you had to pay $10 for your spot in line, which would go to local charities fighting homelessness and hunger.
It didn't quite work out that way, but 6.5 million people still ponied up their money and held hands with their neighbors all the same. Other than that, you don't see human chains much. The one seen recently in India, however, was downright powerful.