My understanding of this shit is some rap song had six seven in it where he was referring to his local hood. I doubt it was a good song, rap never really recovered from the cribs era.
It's Zalgo script, created back in the early 2000's and it combines 3 different character sets. Your computer has to be able to show UTF-8. If you merge Combining Diacritical Marks (U+0300 - U+036F), Greek and Coptic (U+0370 - U+3FF) and Cyrillic (U+0400 - U+04FF) allows you to Zalgo.