Catching Spammer with multiple changes of case + char/numbers

[kech61]

I have a flood of Spammers going through your plugin.
It would be easy to filter those if there would be an option to filter Names where more than 4 (to configure) changes occour between lower/upper charakters and charakter/numbers.

See such names here:

ID #6255: XiSW8AbFeGyJfRR
ID #6254: MLirmDNvmaWa6vuD7zi
ID #6253: 11EkicRTGFQ7IRgsBys
ID #6252: iA1PNHfyD1U6hjnYP4
ID #6251: jfNB6Vy07jE4ptWI
ID #6250: MS70CGysp4ZGUr
ID #6249: 1M86kqOTsTHzGvj
ID #6248: AGfCQBRygGjnQLoLJU2H
ID #6247: V7L3DCgCtXnFOTH
ID #6246: YXRMV6Ibkh6xTH
ID #6244: REpHGulm2Rux
ID #6243: 1IBxQ7fQzEeq9g8xbf
ID #6242: Sn6t1hIgAw

Best regards