It's apparent from the kudos being handed out that a lot of people are unsure about what exactly flaming and spamming is. In the interests of education, you can find definitions below:

Flame

See this link for the full text. - link [en.wikipedia.org]

Flaming is the act of posting messages that are deliberately hostile and insulting, usually in the social context of a discussion board (usually on the Internet).

Spam

See this link for full text - link [en.wikipedia.org]

Spamming is commonly defined as the sending of unsolicited bulk e-mail - that is, email that was not asked for (unsolicited) and received by multiple recipients (bulk). A further common definition of spam restricts it to unsolicited commercial e-mail, a definition that does not consider non-commercial solicitations such as political or religious pitches, even if unsolicited, as spam.

In our case, of course, read "email" to mean "post".

So there you have it. If you see either of these behaviours, feel free to kudos them with flame or spam. If you still aren't sure what flame or spam is, then best to leave the thumbs down button alone for now, please.