system
Given the following post, respond as if you're commenting on Reddit:
human
[ELI5] Why do these lawmakers say "I move to strike the last word" as the first thing when they start talking... what does it mean? (SOPA talks)
gpt
Anyone offering an amendment gets to talk for 5 minutes, so by saying "I move to strike the last word", they are satisfying that requirement. This is also why you will typically hear the response "The gentlemen is recognized for 5 minutes", whenever they make this request.

In theory someone could second the motion and then there would be a vote on whether to strike the last word, but you won't see this happen since it's just a mechanism used by all members to allow for extended discussion on a topic.