The problem with poker

Alright. It's finally become clear that people who play online are just too stupid to fold. You can tell them a consistent story all the way to the river and you can see through the screen as they shrug their shoulders and toss in their last chips, knowing that they're beat.

Full Tilt Poker Game #6005794296: $20 + $2 Sit & Go (45724711), Table 1 - 15/30 - No Limit Hold'em - 14:13:39 ET - 2008/04/12
Seat 1: (1,470)
Seat 2: hero (1,470)
Seat 3: (1,500)
Seat 4: villain (1,545)
Seat 5: goat (1,545)
Seat 6: (1,470)
hero posts the small blind of 15
Seat 3 posts the big blind of 30
The button is in seat #1
*** HOLE CARDS ***

I'm going to keep my cards secret for now.

Dealt to hero [?? ??]
villain calls 30
goat calls 30
Seat 6 folds
Seat 1 folds
hero raises to 150

Standard raise - 2 limpers = 5xBB

Seat 3 folds
villain calls 120
goat calls 120
*** FLOP *** [9d 6s 4d]
hero checks
villain bets 270
goat calls 270
hero raises to 600

3x check-raise

villain calls 330
goat calls 330
*** TURN *** [9d 6s 4d] [2h]
hero bets 720, and is all in

Now let's just pause here. If you were in their spot, what is the WORST possible hand I could reasonably have (if I'm not bluffing with nothing at all).

Remember: I raised pre-flop, I check-raised the flop and went all-in on the turn.

A9?

I could have an overpair, I could have flopped a set.

villain calls 720
goat folds
hero shows [Kh 7h]
villain shows [Ac 4c]

WTF?!?! SECOND TO BOTTOM PAIR?!

*** RIVER *** [9d 6s 4d 2h] [Qd]
hero shows King Queen high
villain shows a pair of Fours
villain wins the pot (3,720) with a pair of Fours
hero stands up
*** SUMMARY ***
Total pot 3,720 | Rake 0
Board: [9d 6s 4d 2h Qd]
Seat 1: (button) didn't bet (folded)
Seat 2: hero (small blind) showed [Kh 7h] and lost with King Queen high
Seat 3: (big blind) folded before the Flop
Seat 4: villain showed [Ac 4c] and won (3,720) with a pair of Fours
Seat 5: goat folded on the Turn
Seat 6: didn't bet (folded)

Crispin is right. Bluffing online just doesn't work.