Commenting: Telling other people why they suck.
Facebooking: Avoiding work, real life relationships. Or you are collecting virtual farm animals.
Skyping: Multimedia sexting.
Sharing: Only applicable to virtual items like funny pictures, online news articles, or some polemical op-ed … money, goods, or services exempt.
File sharing: Sharing virtual items with some monetary value.
Tweeting: Expressing short opinions … often regrettable ones … to the general populace.