Haunted swing

I had many news (bad news) to report on but I thought this could cheer you people up, as well as being a good chance to laugh at the whole subject. This must be the spookiest paranormal phenomenon you've ever witnessed: a swing that swings itself!

El misterio de la hamaca que se mueve sola, via Gran Ímpetu

I'm always amazed of the ways people find to make their lives more interesting. I photograph things; I even go to places to photograph specific things. I read books about subjects I don't quite understand or can barely grasp. I'm learning a language where everything seems to be upside down relative to my native tongue. Other people do stranger things to get their "fix", like jumping off bridges with a rope tied to their ankles, or smoking mushrooms, or praying. But getting yourself to believe there's a swing that moves by itself must be among the most ridiculous ways to spice up your earthly life.

Some people in Firmat, a town southwest of Rosario, believe there's a swing that moves by itself. No, before you laugh at it, it's not the wind, and just in case, the other two swings in the same set aren't moving. The movement of the swing is pronounced, and it really doesn't look abnormal — the chain that holds it is not tensed or fully extended, so there's no invisible child sitting on it, and the balance is steady and shows the homogeneous deceleration that is to be expected in a simple gravity pendulum, only it regains acceleration every now and then and so continues to swing for a while (the video is not clear at all).

I'm not going to judge the simple-minded folks who believe a swing can move by itself. There are probably many people in Firmat who'd swear they see the swing moving without any force being exerted over it by natural means. I don't think it's a conspiracy to distract attention from something else. I can't really discard it as a joke. So?

So, which of these two possibilities is more likely to be true?

1. The swing really moves by itself or through undetectable means outside the limits of human science and common experience.
2. Somebody outside the camera's field of view is pulling the swing with a string.

Note these don't exclude others and can overlap with others as well (though 1 and 2 can only overlap if the "somebody" in question is a ghost or the string is made of ectoplasm or something like that). For example, the video that shows the swing moving could be manipulated. Or there could actually be a strong wind but the other two swings in the set are tied to the ground with a fine string you can't see in the video. Or it could just be a joke.

People are already claiming the spirit of a child is swinging in the swing, and some say they've talked to the swing (that must have been a truly weird experience). The mayor of Firmat only said "We can't find a rational explanation", and, rather disappointedly, noted that he'd like journalists and curious visitors to come to his town for different reasons. (Maybe the ghost in the swing will take his cue from that.)