diff --git a/mastodon/check-instance-ban.py b/mastodon/check-instance-ban.py
new file mode 100755
index 0000000..c01ed45
--- /dev/null
+++ b/mastodon/check-instance-ban.py
@@ -0,0 +1,101 @@
+#!/usr/bin/python3
+import requests
+import hashlib
+import pickle
+import time
+import json
+import sys
+import os
+
+DOMAIN = 'mastodon.social'
+
+def main():
+	global DOMAIN
+	if len(sys.argv) > 1:
+		DOMAIN = sys.argv[1]
+
+	res = http_get('https://api.joinmastodon.org/servers?language=en&category=&region=&ownership=&registrations=')
+	res = json.loads(res.text)
+
+	failed_servers = 0
+	banned_by = []
+	for it in res:
+		print('checking "{}" has banned "{}"... '\
+			.format(it['domain'], DOMAIN))
+		acct = get_admin_account(it['domain'])
+		if acct == False:
+			failed_servers += 1
+			continue
+
+		r = http_get('https://'+DOMAIN+'/'+acct, True)
+		if r == False:
+			failed_servers += 1
+			continue
+		if r.status_code == 404:
+			banned_by.append(it['domain'])
+			print('YES')
+		else:
+			print('NO')
+	print()
+	print('////////')
+	print('Instance: '+DOMAIN)
+	print('Banned by: '+json.dumps(banned_by))
+	print('Servers count: total={} | failed={} | used_in_percentage={}'.format(len(res), failed_servers, len(res)-failed_servers))
+	print('Percentage of bans: '+str( (len(banned_by) * 100) / (len(res)-failed_servers) )+'% has banned the instance')
+	print()
+
+def http_get(url, show=False):
+	try:
+		fl = '/tmp/.check-instance-ban__'+md5(url)
+		if os.path.exists(fl):
+			ts = int(os.path.getmtime(fl))
+			secs = int(time.time()) - ts
+			if secs <= 1800: # cache 30 mins
+				if show:
+					print('  HTTP-cached: '+url)
+				return cache_read(fl)
+		if show:
+			print('  HTTP: '+url)
+		r = requests.get(url, timeout=5)
+		cache_write(fl, r)
+		return r
+	except requests.exceptions.ConnectionError:
+		pass
+	return False
+
+def cache_read(f):
+	with open(f,'rb') as in_file:
+		return pickle.load(in_file)
+	return None
+
+def cache_write(f,o):
+	with open(f, 'wb') as out_file:
+		pickle.dump(o, out_file)
+	return True
+
+def get_admin_account(domain):
+	r = http_get('https://'+domain+'/api/v1/instance')
+	if r == False:
+		return False
+	js = json.loads(r.text)
+	return '@'+js['contact_account']['username']+'@'+domain
+
+def md5(s):
+	return hashlib.md5(s.encode('utf8')).hexdigest()
+
+def readf(f):
+	r = open(f,'r')
+	c = r.read().strip()
+	r.close()
+	return c
+
+def appenf(f,c):
+	return writef(f,c,'a')
+
+def writef(f,c,t='w'):
+	w = open(f,t)
+	w.write(c)
+	w.close()
+
+if __name__ == '__main__':
+	main()