The important thing to understanding filibusters is that they're a dirty, dirty hack. They were never really intended to be part of the legislative process, they're just some enterprising senators noticing and exploiting some loopholes in the senate's debate rules.
While the House puts some limits on debates, to move things along, the Senate is a more deliberative body (by design) and therefore doesn't vote on an issue until it has been completely debated. There is no strict definition of "completely debated" beyond "someone still has something to say." As any half-awake hacker no doubt will notice, this means that you can prevent a law from getting voted on, and therefore passing, by simply not ending the debate. This is what a filibuster is.
There are technically some restrictions around debate, and the band-aid fix that a supermajority vote can stop debate and bring a vote, but that's about the only thing stopping it in practice.
The main technical restriction is that, if the Senate doesn't have anything else to do, any one Senator only gets one monologue. They can't stop one day, and then filibuster again the next day. This rule can be stretched, but not broken. Hence, the content of most filibusters tend to be long space-fillers, which is what you're seeing. There's also a rule that the debate must be 'on topic,' but that's too vaguely defined to be worth anything. Famously, one Senator said something to the effect of "this law is not in the interests of my constituents, who are as follows:" and then proceed to literally read the phone book for a few hours.
Filibuster the way it's used today is a dirty hack. But Sen. Paul is actually using it legitimately by standing and debating/speaking instead of just declaring 'I filibuster' and going home (implying that he would speak forever but doesn't need to since it's merely a formality). It's actually the most refreshing political action I've seen in a while. They're talking through the night, live now: http://www.c-span.org/Live-Video/C-SPAN2/
My favorite so far was Marco Rubio quoting a line in the godfather:
"... 'A lawyer with his briefcase can steal more than a hundred men with guns.' Now, I don't know how the hell that relates to this argument, but I thought it was a good quote."
Based on Sen. Al D'Amato's 1986 23.5 hour filibuster of a military bill. Another of his filibusters in 1992 involved him singing 'South of the Border.' EDIT: typos.
While the House puts some limits on debates, to move things along, the Senate is a more deliberative body (by design) and therefore doesn't vote on an issue until it has been completely debated. There is no strict definition of "completely debated" beyond "someone still has something to say." As any half-awake hacker no doubt will notice, this means that you can prevent a law from getting voted on, and therefore passing, by simply not ending the debate. This is what a filibuster is.
There are technically some restrictions around debate, and the band-aid fix that a supermajority vote can stop debate and bring a vote, but that's about the only thing stopping it in practice.
The main technical restriction is that, if the Senate doesn't have anything else to do, any one Senator only gets one monologue. They can't stop one day, and then filibuster again the next day. This rule can be stretched, but not broken. Hence, the content of most filibusters tend to be long space-fillers, which is what you're seeing. There's also a rule that the debate must be 'on topic,' but that's too vaguely defined to be worth anything. Famously, one Senator said something to the effect of "this law is not in the interests of my constituents, who are as follows:" and then proceed to literally read the phone book for a few hours.