Over on Reddit, people are sharing their stories of wedding disasters. Here are all the comments that involve DJs:
We had a low budget wedding, so no live band, just a dj. We gave him the music for the first husband/wife song at rehearsal and all was good. Once it was time for the dance he played the wrong song 3 times, until my husband had it and left me standing in the middle while he went to put the damn music himself.
At the hotel reception the DJ could not figure out how to get to the venue due to road closures (and being unfamiliar with the area). The first half of the reception was basically quiet until the groomsmen found that the restaurant in the hotel had a jukebox. The restaurant let them move it to the banquet hall where they payed quarters for music.
The DJ took the money and ran (went out of business and didn't bother letting me know, so we played iPhone music on a little speaker all night)
My SO insisted people wouldn't dance to a playlist. He invited a friend who was a DJ. That played awful odd technomusic. He had all sorts of material with him, of which he previously had said he'd not bring much. He arrived with a van full. The circuits of the bar weren't equipped for that but thankfully they held for the hour awful DJ played.
DJ was absolute trash. He came highly recommended, but ended up playing all of the songs on our do-not-play list.