micsu on "[Plugin: Wordfence Security] Login Security not working?"

Thanks for the input, mwrusnak!
Yes, now that I checked that more carefully, I also see that the accessed document size has decreased after locking the user out from login:

"POST /wp-login.php HTTP/1.0" 200 5413 "-" "-"
"POST /wp-login.php HTTP/1.0" 200 5419 "-" "-"
"POST /wp-login.php HTTP/1.0" 200 5415 "-" "-"
"POST /wp-login.php HTTP/1.0" 200 5410 "-" "-"
"POST /wp-login.php HTTP/1.0" 200 1540 "-" "-"
"POST /wp-login.php HTTP/1.0" 200 1540 "-" "-"
"POST /wp-login.php HTTP/1.0" 200 1540 "-" "-"
"POST /wp-login.php HTTP/1.0" 200 1540 "-" "-"
(and this smaller access repeats 93 times)