The list is almost endless...
But basically anything that should be personal business can become the business of the congregation and will be debated and gossipped over.
Brother Reaching-out-to-be-an-MS was seen renting an R-rated movie. Before anyone says a word to him about it, 90% of the congregation has already found out and by the time it gets back to him, or worse, an elder, it has gone from being "The Matrix" to "Lesbo Babes in Latex" that he was renting.
Sister Single-but-trying-hard-to-find-a-mate is seen out at lunch with a *gasp* male...but he's not from the hall. Is he a co-worker? Is she dating a worldly guy? Before anyone finds out that its her out-of-town cousin, everyone at the hall is convinced she'll be disfellowshipped for fornication.
Young Brother Young has bought a new car...a 2 door sports car. Before he gets the first tank of gas burned off, he has had three elders, two MSs and several pioneers counsel him on materialism. (No one realizing of course that his used 2 door car cost about half of what the SUVs cost that the elders and MSs are driving).