diff --git a/bitchat.py b/bitchat.py
index a2bbf7c..da479b4 100644
--- a/bitchat.py
+++ b/bitchat.py
@@ -1541,9 +1541,9 @@ async def handle_user_input(self, line: str):
             elif len(new_name) > 20:
                 print("\033[93m⚠ Nickname too long\033[0m")
                 print("\033[90mMaximum 20 characters allowed.\033[0m")
-            elif not all(c.isalnum() or c in '-_' for c in new_name):
+            elif any(c in '\n\r\t\0' for c in new_name):
                 print("\033[93m⚠ Invalid nickname\033[0m")
-                print("\033[90mNicknames can only contain letters, numbers, hyphens and underscores.\033[0m")
+                print("\033[90mNicknames cannot contain control characters.\033[0m")
             elif new_name in ["system", "all"]:
                 print("\033[93m⚠ Reserved nickname\033[0m")
                 print("\033[90mThis nickname is reserved and cannot be used.\033[0m")
@@ -2481,15 +2481,108 @@ async def run(self):
 # Helper functions
 
 def print_banner():
-    """Print the BitChat banner"""
-    print("\n\033[38;5;46m##\\       ##\\   ##\\               ##\\                  ##\\")
-    print("## |      \\__|  ## |              ## |                 ## |")
-    print("#######\\  ##\\ ######\\    #######\\ #######\\   ######\\ ######\\")
-    print("##  __##\\ ## |\\_##  _|  ##  _____|##  __##\\  \\____##\\\\_##  _|")
-    print("## |  ## |## |  ## |    ## /      ## |  ## | ####### | ## |")
-    print("## |  ## |## |  ## |##\\ ## |      ## |  ## |##  __## | ## |##\\")
-    print("#######  |## |  \\####  |\\#######\\ ## |  ## |\\####### | \\####  |")
-    print("\\_______/ \\__|   \\____/  \\_______|\\__|  \\__| \\_______|  \\____/\033[0m")
+    """Print a random BitChat banner"""
+    banners = [
+        # Original LaTeX style banner
+        lambda: (
+            print("\n\033[38;5;46m##\\       ##\\   ##\\               ##\\                  ##\\"),
+            print("## |      \\__|  ## |              ## |                 ## |"),
+            print("#######\\  ##\\ ######\\    #######\\ #######\\   ######\\ ######\\"),
+            print("##  __##\\ ## |\\_##  _|  ##  _____|##  __##\\  \\____##\\\\_##  _|"),
+            print("## |  ## |## |  ## |    ## /      ## |  ## | ####### | ## |"),
+            print("## |  ## |## |  ## |##\\ ## |      ## |  ## |##  __## | ## |##\\"),
+            print("#######  |## |  \\####  |\\#######\\ ## |  ## |\\####### | \\####  |"),
+            print("\\_______/ \\__|   \\____/  \\_______|\\__|  \\__| \\_______|  \\____/\033[0m")
+        ),
+        
+        # Big block letters style
+        lambda: (
+            print("\n\033[38;5;201m██████╗ ██╗████████╗ ██████╗██╗  ██╗ █████╗ ████████╗"),
+            print("██╔══██╗██║╚══██╔══╝██╔════╝██║  ██║██╔══██╗╚══██╔══╝"),
+            print("██████╔╝██║   ██║   ██║     ███████║███████║   ██║   "),
+            print("██╔══██╗██║   ██║   ██║     ██╔══██║██╔══██║   ██║   "),
+            print("██████╔╝██║   ██║   ╚██████╗██║  ██║██║  ██║   ██║   "),
+            print("╚═════╝ ╚═╝   ╚═╝    ╚═════╝╚═╝  ╚═╝╚═╝  ╚═╝   ╚═╝   \033[0m")
+        ),
+        
+        # Graffiti style
+        lambda: (
+            print("\n\033[38;5;196m ▄▄▄▄    ██▓▄▄▄█████▓ ▄████▄   ██░ ██  ▄▄▄      ▄▄▄█████▓"),
+            print("▓█████▄ ▓██▒▓  ██▒ ▓▒▒██▀ ▀█  ▓██░ ██▒▒████▄    ▓  ██▒ ▓▒"),
+            print("▒██▒ ▄██▒██▒▒ ▓██░ ▒░▒▓█    ▄ ▒██▀▀██░▒██  ▀█▄  ▒ ▓██░ ▒░"),
+            print("▒██░█▀  ░██░░ ▓██▓ ░ ▒▓▓▄ ▄██▒░▓█ ░██ ░██▄▄▄▄██ ░ ▓██▓ ░ "),
+            print("░▓█  ▀█▓░██░  ▒██▒ ░ ▒ ▓███▀ ░░▓█▒░██▓ ▓█   ▓██▒  ▒██▒ ░ "),
+            print("░▒▓███▀▒░▓    ▒ ░░   ░ ░▒ ▒  ░ ▒ ░░▒░▒ ▒▒   ▓▒█░  ▒ ░░   "),
+            print("▒░▒   ░  ▒ ░    ░      ░  ▒    ▒ ░▒░ ░  ▒   ▒▒ ░    ░    "),
+            print(" ░    ░  ▒ ░  ░      ░         ░  ░░ ░  ░   ▒     ░      "),
+            print(" ░       ░           ░ ░       ░  ░  ░      ░  ░         "),
+            print("      ░              ░                                   \033[0m")
+        ),
+        
+        # Slant style
+        lambda: (
+            print("\n\033[38;5;33m    ▄▄▄▄    ██▓▄▄▄█████▓ ▄████▄   ██░ ██  ▄▄▄     ▄▄▄█████▓"),
+            print("   ▓█████▄ ▓██▒▓  ██▒ ▓▒▒██▀ ▀█  ▓██░ ██▒▒████▄  ▓  ██▒ ▓▒"),
+            print("   ▒██▒ ▄██▒██▒▒ ▓██░ ▒░▒▓█    ▄ ▒██▀▀██░▒██  ▀█▄▒ ▓██░ ▒░"),
+            print("   ▒██░█▀  ░██░░ ▓██▓ ░ ▒▓▓▄ ▄██▒░▓█ ░██ ░██▄▄▄▄██░ ▓██▓ ░"),
+            print("   ░▓█  ▀█▓░██░  ▒██▒ ░ ▒ ▓███▀ ░░▓█▒░██▓ ▓█   ▓██▒ ▒██▒ ░"),
+            print("   ░▒▓███▀▒░▓    ▒ ░░   ░ ░▒ ▒  ░ ▒ ░░▒░▒ ▒▒   ▓▒█░ ▒ ░░  "),
+            print("   ▒░▒   ░  ▒ ░    ░      ░  ▒    ▒ ░▒░ ░  ▒   ▒▒ ░   ░   "),
+            print("    ░    ░  ▒ ░  ░      ░         ░  ░░ ░  ░   ▒    ░     "),
+            print("    ░       ░           ░ ░       ░  ░  ░      ░  ░       "),
+            print("         ░              ░                                \033[0m")
+        ),
+        
+        # ASCII art style
+        lambda: (
+            print("\n\033[38;5;208m ____  _ _    _____ _           _   "),
+            print("| __ )(_) |_ / ____| |__   __ _| |_ "),
+            print("|  _ \\| | __| |   | '_ \\ / _` | __|"),
+            print("| |_) | | |_| |___| | | | (_| | |_ "),
+            print("|____/|_|\\__|\\____|_| |_|\\__,_|\\__|\033[0m")
+        ),
+        
+        # Modern minimal style
+        lambda: (
+            print("\n\033[38;5;51m┌──────────────────────────────────────┐"),
+            print("│ ██████  ██ ████████  ██████ ██   ██  │"),
+            print("│ ██   ██ ██    ██    ██      ██   ██  │"),
+            print("│ ██████  ██    ██    ██      ███████  │"),
+            print("│ ██   ██ ██    ██    ██      ██   ██  │"),
+            print("│ ██████  ██    ██     ██████ ██   ██  │"),
+            print("│               BitChat                │"),
+            print("└──────────────────────────────────────┘\033[0m")
+        ),
+        
+        # Cyberpunk style
+        lambda: (
+            print("\n\033[38;5;46m╔══════════════════════════════════════════════════════╗"),
+            print("║ ██████  ██ ████████  ██████ ██   ██  █████  ████████ ║"),
+            print("║ ██   ██ ██    ██    ██      ██   ██ ██   ██    ██    ║"),
+            print("║ ██████  ██    ██    ██      ███████ ███████    ██    ║"),
+            print("║ ██   ██ ██    ██    ██      ██   ██ ██   ██    ██    ║"),
+            print("║ ██████  ██    ██     ██████ ██   ██ ██   ██    ██    ║"),
+            print("║                     BitChat v2.0                     ║"),
+            print("╚══════════════════════════════════════════════════════╝\033[0m")
+        ),
+        
+        # Matrix style
+        lambda: (
+            print("\n\033[38;5;82m░▒▓███████▓▒░░▒▓█▓▒░▒▓████████▓▒░ ░▒▓██████▓▒░░▒▓█▓▒░░▒▓█▓▒░░▒▓██████▓▒░▒▓████████▓▒░"),
+            print("░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░   ░▒▓█▓▒░   ░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░░▒▓█▓▒░  ░▒▓█▓▒░   "),
+            print("░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░   ░▒▓█▓▒░   ░▒▓█▓▒░      ░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░░▒▓█▓▒░  ░▒▓█▓▒░   "),
+            print("░▒▓███████▓▒░░▒▓█▓▒░   ░▒▓█▓▒░   ░▒▓█▓▒░      ░▒▓████████▓▒░▒▓████████▓▒░  ░▒▓█▓▒░   "),
+            print("░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░   ░▒▓█▓▒░   ░▒▓█▓▒░      ░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░░▒▓█▓▒░  ░▒▓█▓▒░   "),
+            print("░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░   ░▒▓█▓▒░   ░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░░▒▓█▓▒░  ░▒▓█▓▒░   "),
+            print("░▒▓███████▓▒░░▒▓█▓▒░   ░▒▓█▓▒░    ░▒▓██████▓▒░░▒▓█▓▒░░▒▓█▓▒░▒▓█▓▒░░▒▓█▓▒░  ░▒▓█▓▒░   \033[0m")
+        )
+    ]
+    
+    # Randomly select and execute a banner
+    selected_banner = random.choice(banners)
+    selected_banner()
+    
+    # Common footer for all banners
     print("\n\033[38;5;40m━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\033[0m")
     print("\033[37mDecentralized • Encrypted • Peer-to-Peer • Open Source\033[0m")
     print(f"\033[37m         bitchat@-python {VERSION} @kaganisildak\033[0m")