noun
crossing the line; going too far
Internet slang for overstepping a boundary, similar to 一線を越える. Used when someone's words or actions become inappropriate or excessive.
See also: 一線を越える
あのコメントはライン越えだと思う。
I think that comment crossed the line.
冗談でもライン越えは許されない。
Even as a joke, going too far is not acceptable.
A more formal and established expression for crossing a boundary, while ライン越え is casual internet slang.
Compound of ライン (line) and 越え (crossing), modeled on the phrase 一線を越える. The exact origin is uncertain, but it likely emerged in online communities.