I founf this trap while playing through some games in the Budapest Gambit (no, it is not the mate in 8)

I love playing this against unsuspecting d4-players

Any comments

I like it. But is there a way for white to defend? For example, couldn't white play 5.f3 and just get rid of that pesky doubled e file white pawn on e5 (that has to be passively defended? Couldn't white also play 4.f4 instead of 4.Bf4 to discourage black from capturing the pawn with pieces? White doesn't have to fall into that trap.

Have a happy new years day.

f4 badly weakens white's king position and the a7-g8 diagonal. Even though white will be permanently up a pawn, his king will be weak and I'm sure there are a couple of games where black exploited that. In fact, in chess.com's database, black scores 100% win against the f4 move

8 Qd2 would be played by the suspecting.

Change white's eight move for Be3 and then you can get the rook out and move King to g1, but as said, nothing defends better than Qe2.

I think 8.Qd2 is the best, but don't tell my opponents

I think 4...Bb4+ is also a good try, as 5.Nc3 throws away any chance for positional advantage. This looks good too, though. However, the Nxf2 idea is not hard to find in a standard game, so its practical applications are mostly limited to blitz.