diff --git a/.github/ISSUE_TEMPLATE/1.bug_report.yml b/.github/ISSUE_TEMPLATE/1.bug_report.yml
index 4f420416b..9cdf813f7 100644
--- a/.github/ISSUE_TEMPLATE/1.bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/1.bug_report.yml
@@ -8,6 +8,17 @@ body:
         Make sure that you are submitting a new bug that was not previously reported or already fixed.
 
         Please use a concise and distinct title for the issue.
+  - type: textarea
+    attributes:
+      label: Steps to reproduce the problem
+      description: What were you trying to do?
+      value: |
+        1.
+        2.
+        3.
+        ...
+    validations:
+      required: true
   - type: input
     attributes:
       label: Expected behaviour
@@ -20,17 +31,6 @@ body:
       description: What happened?
     validations:
       required: true
-  - type: textarea
-    attributes:
-      label: Steps to reproduce the problem
-      description: What were you trying to do?
-      value: |
-        1.
-        2.
-        3.
-        ...
-    validations:
-      required: true
   - type: textarea
     attributes:
       label: Specifications
diff --git a/.ruby-version b/.ruby-version
index b50214693..75a22a26a 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.0.2
+3.0.3
diff --git a/Dockerfile b/Dockerfile
index f5de24210..309ec06f4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -27,7 +27,7 @@ RUN ARCH= && \
 	mv node-v$NODE_VER-linux-$ARCH /opt/node
 
 # Install Ruby 3.0
-ENV RUBY_VER="3.0.2"
+ENV RUBY_VER="3.0.3"
 RUN apt-get update && \
   apt-get install -y --no-install-recommends build-essential \
     bison libyaml-dev libgdbm-dev libreadline-dev libjemalloc-dev \
diff --git a/FEDERATION.md b/FEDERATION.md
new file mode 100644
index 000000000..cd1957cbd
--- /dev/null
+++ b/FEDERATION.md
@@ -0,0 +1,30 @@
+## ActivityPub federation in Mastodon
+
+Mastodon largely follows the ActivityPub server-to-server specification but it makes uses of some non-standard extensions, some of which are required for interacting with Mastodon at all.
+
+Supported vocabulary: https://docs.joinmastodon.org/spec/activitypub/
+
+### Required extensions
+
+#### Webfinger
+
+In Mastodon, users are identified by a `username` and `domain` pair (e.g., `Gargron@mastodon.social`).
+This is used both for discovery and for unambiguously mentioning users across the fediverse. Furthermore, this is part of Mastodon's database design from its very beginnings.
+
+As a result, Mastodon requires that each ActivityPub actor uniquely maps back to an `acct:` URI that can be resolved via WebFinger.
+
+More information and examples are available at: https://docs.joinmastodon.org/spec/webfinger/
+
+#### HTTP Signatures
+
+In order to authenticate activities, Mastodon relies on HTTP Signatures, signing every `POST` and `GET` request to other ActivityPub implementations on behalf of the user authoring an activity (for `POST` requests) or an actor representing the Mastodon server itself (for most `GET` requests).
+
+Mastodon requires all `POST` requests to be signed, and MAY require `GET` requests to be signed, depending on the configuration of the Mastodon server.
+
+More information on HTTP Signatures, as well as examples, can be found here: https://docs.joinmastodon.org/spec/security/#http
+
+### Optional extensions
+
+- Linked-Data Signatures: https://docs.joinmastodon.org/spec/security/#ld
+- Bearcaps: https://docs.joinmastodon.org/spec/bearcaps/
+- Followers collection synchronization: https://git.activitypub.dev/ActivityPubDev/Fediverse-Enhancement-Proposals/src/branch/main/feps/fep-8fcf.md
diff --git a/app/models/canonical_email_block.rb b/app/models/canonical_email_block.rb
index a8546d65a..be8c45bfe 100644
--- a/app/models/canonical_email_block.rb
+++ b/app/models/canonical_email_block.rb
@@ -15,7 +15,7 @@ class CanonicalEmailBlock < ApplicationRecord
 
   belongs_to :reference_account, class_name: 'Account'
 
-  validates :canonical_email_hash, presence: true
+  validates :canonical_email_hash, presence: true, uniqueness: true
 
   def email=(email)
     self.canonical_email_hash = email_to_canonical_email_hash(email)
diff --git a/spec/models/account_spec.rb b/spec/models/account_spec.rb
index 03d6f5fb0..65e6714c0 100644
--- a/spec/models/account_spec.rb
+++ b/spec/models/account_spec.rb
@@ -5,6 +5,37 @@ RSpec.describe Account, type: :model do
     let(:bob) { Fabricate(:account, username: 'bob') }
     subject { Fabricate(:account) }
 
+    describe '#suspend!' do
+      it 'marks the account as suspended' do
+        subject.suspend!
+        expect(subject.suspended?).to be true
+      end
+
+      it 'creates a deletion request' do
+        subject.suspend!
+        expect(AccountDeletionRequest.where(account: subject).exists?).to be true
+      end
+
+      context 'when the account is of a local user' do
+        let!(:subject) { Fabricate(:account, user: Fabricate(:user, email: 'foo+bar@domain.org')) }
+
+        it 'creates a canonical domain block' do
+          subject.suspend!
+          expect(CanonicalEmailBlock.block?(subject.user_email)).to be true
+        end
+
+        context 'when a canonical domain block already exists for that email' do
+          before do
+            Fabricate(:canonical_email_block, email: subject.user_email)
+          end
+
+          it 'does not raise an error' do
+            expect { subject.suspend! }.not_to raise_error
+          end
+        end
+      end
+    end
+
     describe '#follow!' do
       it 'creates a follow' do
         follow = subject.follow!(bob)