Media is still accessible via it's original URL after its been sent to the recycle bin

src/Umbraco.Core/Media/UmbracoFileProperty.cs

@@ -0,0 +1,53 @@
+using System.Linq;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using Umbraco.Core.Models;
+
+namespace Umbraco.Core.Media
+{
+    public class UmbracoFileProperty
+    {
+        private readonly IMedia _media;
+
+        public UmbracoFileProperty(IMedia media)
+        {
+            _media = media;
+        }
+
+        private Property Property()
+        {
+            return _media.Properties.FirstOrDefault(x => x.Alias.InvariantEquals("umbracoFile"));
+        }
+
+        public string Src 
+        {
+            get
+            {
+                var value = Property()?.Value as string;
+                if (value != null && value.DetectIsJson())
+                {
+                    // the property value is a JSON serialized image crop data set - grab the "src" property as the file source
+                    var jObject = JsonConvert.DeserializeObject<JObject>(value);
+                    value = jObject != null ? jObject.GetValueAsString("src") : value;
+                }
+                return value;
+            }
+            set
+            {
+                var property = Property();
+                if (property == null)
+                {
+                    return;
+                }
+                var filename = property?.Value as string;
+                if (filename != null && filename.DetectIsJson())
+                {
+                    var jObject = JsonConvert.DeserializeObject<JObject>(value);
+                    jObject.Property("src").Value = value;
+                }
+
+                property.Value = value;
+            }
+        }
+    }
+}

src/Umbraco.Core/Models/Media.cs

@@ -117,6 +117,7 @@ public override void ChangeTrashedState(bool isTrashed, int parentId = -20)
             Trashed = isTrashed;
             //The Media Recycle Bin Id is -21 so we correct that here
             ParentId = parentId == -20 ? -21 : parentId;
+
         }
     }
-}
+}

src/Umbraco.Core/Services/IMediaService.cs

@@ -112,7 +112,7 @@ public interface IMediaService : IContentServiceBase
         /// <param name="mediaTypeAlias">Alias of the <see cref="IMediaType"/></param>
         /// <param name="userId">Optional id of the user creating the media item</param>
         /// <returns><see cref="IMedia"/></returns>
-        IMedia CreateMedia(string name, Guid parentId, string mediaTypeAlias, int userId = 0);
+        IMedia CreateMedia(string name, Guid parentId, string mediaTypeAlias, int userId = 0);
 
         /// <summary>
         /// Creates an <see cref="IMedia"/> object using the alias of the <see cref="IMediaType"/>

src/Umbraco.Core/Services/MediaService.cs

@@ -4,12 +4,14 @@
 using System.Globalization;
 using System.IO;
 using System.Linq;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Xml.Linq;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Events;
 using Umbraco.Core.IO;
 using Umbraco.Core.Logging;
+using Umbraco.Core.Media;
 using Umbraco.Core.Models;
 using Umbraco.Core.Persistence;
 using Umbraco.Core.Persistence.DatabaseModelDefinitions;
@@ -797,6 +799,7 @@ public Attempt<OperationStatus> Move(IMedia media, int parentId, int userId = 0)
                     if (media.Trashed)
                     {
                         media.ChangeTrashedState(false, parentId);
+                        UnobfuscateTrashedMedia(media);
                     }
                     Save(media, userId, false); //no events!
 
@@ -1133,6 +1136,8 @@ private Attempt<OperationStatus> MoveToRecycleBinDo(IMedia media, int userId, bo
                     //must be processed with shallowest levels first
                     var descendants = ignoreDescendants ? Enumerable.Empty<IMedia>() : GetDescendants(media).OrderBy(x => x.Level);
 
+                    ObfuscateTrashedMedia(media);
+
                     //Do the updates for this item
                     var repository = RepositoryFactory.CreateMediaRepository(uow);
                     repository.DeleteContentXml(media);
@@ -1144,8 +1149,9 @@ private Attempt<OperationStatus> MoveToRecycleBinDo(IMedia media, int userId, bo
                     {
                         repository.DeleteContentXml(descendant);
                         descendant.ChangeTrashedState(true, descendant.ParentId);
+                        ObfuscateTrashedMedia(descendant);
                         repository.AddOrUpdate(descendant);
-
+                        
                         moveInfo.Add(new MoveEventInfo<IMedia>(descendant, descendant.Path, descendant.ParentId));
                     }
 
@@ -1161,6 +1167,58 @@ private Attempt<OperationStatus> MoveToRecycleBinDo(IMedia media, int userId, bo
             }
         }
 
+        private void ObfuscateTrashedMedia(IMedia media)
+        {
+            var umbracoFile = new UmbracoFileProperty(media).Src;
+            if (umbracoFile == null)
+            {
+                return;
+            }
+            var filename = Path.GetFileName(umbracoFile);
+            var newUmbracoFile = MediaPath(umbracoFile) + ObfuscateFilename(filename);
+            MoveFile(umbracoFile, newUmbracoFile);
+            media.SetValue("umbracoFile", newUmbracoFile);
+        }
+
+        private void UnobfuscateTrashedMedia(IMedia media)
+        {
+            var umbracoFile = new UmbracoFileProperty(media);
+            var path = umbracoFile.Src;
+            var filename = Path.GetFileName(path);
+            if (HasBeenObfuscated(filename)) 
+            {
+                var newUmbracoFile = MediaPath(path) + UnobfuscateFilename(filename);
+                MoveFile(path, newUmbracoFile);
+                umbracoFile.Src = newUmbracoFile;
+            }
+        }
+
+        private string MediaPath(string umbracoFile)
+        {
+            return Path.GetDirectoryName(umbracoFile).Replace("\\", "/") + "/";
+        }
+
+        private void MoveFile(string from, string to)
+        {
+            _mediaFileSystem.CopyFile(from, to);
+            _mediaFileSystem.DeleteFile(from);
+        }
+
+        private string ObfuscateFilename(string filename)
+        {
+            return Guid.NewGuid().ToString("D") + "---" + filename;
+        }
+
+        private string UnobfuscateFilename(string filename)
+        {
+            return filename.Split(new[] {"---"}, 2, StringSplitOptions.RemoveEmptyEntries)[1];
+        }
+
+        private bool HasBeenObfuscated(string filename)
+        {
+            return Regex.IsMatch(filename, @"^[0-9A-Fa-f]{8}[-]?(?:[0-9A-Fa-f]{4}[-]?){3}[0-9A-Fa-f]{12}---");
+        }
+
 
         /// <summary>
         /// Permanently deletes an <see cref="IMedia"/> object as well as all of its Children.
@@ -1381,6 +1439,14 @@ private IEnumerable<IMedia> UpdatePropertiesOnChildren(IEnumerable<IMedia> child
                 if (parentTrashed != child.Trashed)
                 {
                     child.ChangeTrashedState(parentTrashed, child.ParentId);
+                    if (parentTrashed)
+                    {
+                        ObfuscateTrashedMedia(child);
+                    }
+                    else
+                    {
+                        UnobfuscateTrashedMedia(child);
+                    }
                 }
 
                 eventInfo.Add(new MoveEventInfo<IMedia>(child, originalPath, child.ParentId));

src/Umbraco.Core/Umbraco.Core.csproj

@@ -370,6 +370,7 @@
     <Compile Include="Media\TypeDetector\RasterizedTypeDetector.cs" />
     <Compile Include="Media\TypeDetector\SVGDetector.cs" />
     <Compile Include="Media\TypeDetector\TIFFDetector.cs" />
+    <Compile Include="Media\UmbracoFileProperty.cs" />
     <Compile Include="Models\AuditEntry.cs" />
     <Compile Include="Models\Consent.cs" />
     <Compile Include="Models\ConsentExtensions.cs" />