Comment by layer8

I wanted to see the intersection between syntactically valid URLs and email addresses, but just entering the URL regex (cf. below) already takes too long to process for the page.

[\-a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([\-a-zA-Z0-9()@:%_+.~#?&//=]*)

(source: https://stackoverflow.com/a/3809435/623763)