Spamming is sending unwanted messages to other users. Sometimes spamming happens "on accident"--users forward something they find funny or interesting to their friends, who might not really care about the message at all. Other times, spamming happens on purpose--users send out many messages to harass or annoy other users.

Spamming can happen through email, online chat, social networking (like Facebook), and even text messages.

Spamming might be considered a from of cyberbullying, depending on how it is used. It definitely breaks the rules of netiquette.