"Your selected password is already being used by SwiftyFan05. Please choose another password."

Somebody isn't sanitizing their inputs properly. Like putting a bandaid on a heart attack

Lol I recently have found the opposite!

they don't specify a limit so 64 character password it is.

Hunter2

A great place for a correcthorsebatterystaple-style-password, which is technically a very strong password.

64 characters picked at random in [a-zA-Z0-9_] is perfectly fine if password is your only option. Special character do not increase significantly the difficulty of bruteforcing it, but introduce the risk of having to manually type "}à.å÷Â!!ç-×ô@¸Á¢±ãÕß>>úÓ}¼º¤«<_`àÅû§Æ]*ÂñçÌÿ§à®&ܱ=Ú-´ð¹é$.>=;Ö if something goes catastrophically wrong.

It's actually nice they have underscore. 😀
Yes because if you choose 8 characters at random, with 25 small + 25 big letters and 10 numeric, it* only 60^8 = 167,961,600,000,000 combinations.
I think the problem is more if the system allows brute force with thousands of erroneous attempts.
Then statistically any hacker can attempt several accounts, and ultimately get lucky. But by all means, put the responsibility to the user, users are the experts right!?
I never got the frantic excessive entropy mindset, when the problem is much simpler to not allow crackers endless attempts. You can allow 50 attempts, and chances would be very slim to guess even pretty moronic passwords.

What's even worse is when they REQUIRE big and small and numbers to maximize entropy, they actually make statistically FEWER attempts necessary to brute force it.
A standard Microsoft introduced in the 90's, and FUCKING almost everybody is using, despite it's a 100% moronic requirement.
Instead just warn against passwords that can be guessed by logic, or can be found in a dictionary.

Try this one, has lots of special characters: a_a_a_a_a_a_a_a

recently did one that only cared about being very long, so i typed thispasswordisfuckinglong and it took it

"for best results, your password should be the street you grew up on or your favourite book"

At least if you ever forget it, they'll be able to email it to you.

I hate these arbitrary limitations of 16 characters, 25 is unbreakable and some sites won't allow longer than 16 20, I've even had one site not allow over 6.

I mean, 63^6 is a lot of possibilities, but just make the password longer to increase its security.

Blocking out special characters is dumb, but as others have pointed out, they're probably not sanitizing inputs.

Use a password manager

You might want to try out: https://libraryofbabel.info/random.cgi

Ah, I've done that before, 1/100 odds it's because someone doesn't want to fuck with RegEx.