Possible fix for #1523, im not testing that though :D

src/NadekoBot/Modules/NSFW/NSFW.cs

@@ -4,7 +4,6 @@ using Newtonsoft.Json.Linq;
 using System;
 using System.Linq;
 using System.Threading.Tasks;
-using System.Net.Http;
 using NadekoBot.Extensions;
 using System.Threading;
 using System.Collections.Concurrent;
@@ -15,7 +14,6 @@ using NadekoBot.Modules.Searches.Common;
 using NadekoBot.Modules.Searches.Services;
 using NadekoBot.Modules.NSFW.Exceptions;
 
-//todo static httpclient
 namespace NadekoBot.Modules.NSFW
 {
     public class NSFW : NadekoTopLevelModule<SearchesService>
@@ -160,10 +158,7 @@ namespace NadekoBot.Modules.NSFW
             try
             {
                 JToken obj;
-                using (var http = new HttpClient())
+                obj = JArray.Parse(await _service.Http.GetStringAsync($"http://api.oboobs.ru/boobs/{new NadekoRandom().Next(0, 10330)}").ConfigureAwait(false))[0];
-                {
-                    obj = JArray.Parse(await http.GetStringAsync($"http://api.oboobs.ru/boobs/{new NadekoRandom().Next(0, 10330)}").ConfigureAwait(false))[0];
-                }
                 await Context.Channel.SendMessageAsync($"http://media.oboobs.ru/{obj["preview"]}").ConfigureAwait(false);
             }
             catch (Exception ex)
@@ -178,10 +173,7 @@ namespace NadekoBot.Modules.NSFW
             try
             {
                 JToken obj;
-                using (var http = new HttpClient())
+                obj = JArray.Parse(await _service.Http.GetStringAsync($"http://api.obutts.ru/butts/{new NadekoRandom().Next(0, 4335)}").ConfigureAwait(false))[0];
-                {
-                    obj = JArray.Parse(await http.GetStringAsync($"http://api.obutts.ru/butts/{new NadekoRandom().Next(0, 4335)}").ConfigureAwait(false))[0];
-                }
                 await Context.Channel.SendMessageAsync($"http://media.obutts.ru/{obj["preview"]}").ConfigureAwait(false);
             }
             catch (Exception ex)

src/NadekoBot/Modules/Searches/Common/SearchImageCacher.cs

@@ -20,18 +20,25 @@ namespace NadekoBot.Modules.Searches.Common
 
         private readonly SortedSet<ImageCacherObject> _cache;
         private readonly Logger _log;
+        private readonly HttpClient _http;
 
         public SearchImageCacher()
         {
+            _http = new HttpClient();
+            _http.AddFakeHeaders();
+
             _log = LogManager.GetCurrentClassLogger();
             _rng = new NadekoRandom();
             _cache = new SortedSet<ImageCacherObject>();
         }
 
-        public async Task<ImageCacherObject> GetImage(string tag, bool forceExplicit, DapiSearchType type)
+        public async Task<ImageCacherObject> GetImage(string tag, bool forceExplicit, DapiSearchType type,
+            HashSet<string> blacklistedTags = null)
         {
             tag = tag?.ToLowerInvariant();
 
+            blacklistedTags = blacklistedTags ?? new HashSet<string>();
+
             if (type == DapiSearchType.E621)
                 tag = tag?.Replace("yuri", "female/female");
 
@@ -63,6 +70,9 @@ namespace NadekoBot.Modules.Searches.Common
                 else
                 {
                     var images = await DownloadImages(tag, forceExplicit, type).ConfigureAwait(false);
+                    images = images
+                        .Where(x => x.Tags.All(t => !blacklistedTags.Contains(t)))
+                        .ToArray();
                     if (images.Length == 0)
                         return null;
                     var toReturn = images[_rng.Next(images.Length)];
@@ -117,14 +127,10 @@ namespace NadekoBot.Modules.Searches.Common
                     break;
             }
                 
-            using (var http = new HttpClient())
-            {
-                http.AddFakeHeaders();
-                
             if (type == DapiSearchType.Konachan || type == DapiSearchType.Yandere || 
                 type == DapiSearchType.E621 || type == DapiSearchType.Danbooru)
             {
-                    var data = await http.GetStringAsync(website).ConfigureAwait(false);
+                var data = await _http.GetStringAsync(website).ConfigureAwait(false);
                 return JsonConvert.DeserializeObject<DapiImageObject[]>(data)
                     .Where(x => x.File_Url != null)
                     .Select(x => new ImageCacherObject(x, type))
@@ -133,14 +139,11 @@ namespace NadekoBot.Modules.Searches.Common
 
             return (await LoadXmlAsync(website, type)).ToArray();
         }
-        }
 
         private async Task<ImageCacherObject[]> LoadXmlAsync(string website, DapiSearchType type)
         {
             var list = new List<ImageCacherObject>();
-            using (var http = new HttpClient())
+            using (var reader = XmlReader.Create(await _http.GetStreamAsync(website), new XmlReaderSettings()
-            {
-                using (var reader = XmlReader.Create(await http.GetStreamAsync(website), new XmlReaderSettings()
             {
                 Async = true,
             }))
@@ -160,7 +163,6 @@ namespace NadekoBot.Modules.Searches.Common
                     }
                 }
             }
-            }
             return list.ToArray();
         }
     }

src/NadekoBot/Modules/Searches/Services/SearchesService.cs

@@ -14,11 +14,14 @@ using NadekoBot.Services.Database.Models;
 using System.Linq;
 using Microsoft.EntityFrameworkCore;
 using NadekoBot.Modules.NSFW.Exceptions;
+using System.Net.Http;
 
 namespace NadekoBot.Modules.Searches.Services
 {
     public class SearchesService : INService
     {
+        public HttpClient Http { get; }
+
         private readonly DiscordSocketClient _client;
         private readonly IGoogleApiService _google;
         private readonly DbService _db;
@@ -41,6 +44,8 @@ namespace NadekoBot.Modules.Searches.Services
 
         public SearchesService(DiscordSocketClient client, IGoogleApiService google, DbService db, IEnumerable<GuildConfig> gcs)
         {
+            Http = new HttpClient();
+            Http.AddFakeHeaders();
             _client = client;
             _google = google;
             _db = db;
@@ -128,15 +133,27 @@ namespace NadekoBot.Modules.Searches.Services
 
         public Task<ImageCacherObject> DapiSearch(string tag, DapiSearchType type, ulong? guild, bool isExplicit = false)
         {
-            if (guild.HasValue && GetBlacklistedTags(guild.Value)
+            if (guild.HasValue)
+            {
+                var blacklistedTags = GetBlacklistedTags(guild.Value);
+
+                if (blacklistedTags
                     .Any(x => tag.ToLowerInvariant().Contains(x)))
                 {
                     throw new TagBlacklistedException();
                 }
+
+                var cacher = _imageCacher.GetOrAdd(guild.Value, (key) => new SearchImageCacher());
+
+                return cacher.GetImage(tag, isExplicit, type, blacklistedTags);
+            }
+            else
+            {
                 var cacher = _imageCacher.GetOrAdd(guild ?? 0, (key) => new SearchImageCacher());
 
                 return cacher.GetImage(tag, isExplicit, type);
             }
+        }
 
         public HashSet<string> GetBlacklistedTags(ulong guildId)
         {