They are all procedures for the aspnet security database. At some point, someone has run the SQL script that creates these procedures....do you have the tables as well?
e.g.
aspnet_Membership
aspnet_Roles
aspnet_Users
If your site doesn't run when you remove procedures, you obviously are using this aren't you! Have a look in your web config file, what do you have specified for...
<rolemanager enabled="true" defaultprovider="ChangeControlRoleProvider">
<providers>
<clear />
<add name="SomeRoleProvider" connectionstringname="MyString" applicationname="Myapp" type="System.Web.Security.SqlRoleProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
</providers>
</rolemanager>
<profile>
<providers>
<clear />
<add name="SomeProfileProvider" connectionstringname="MyString" applicationname="Myapp" type="System.Web.Profile.SqlProfileProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
</providers>
</profile>
<membership defaultprovider="SomeMembershipProvider">
<providers>
<clear />
<add name="SomeMembershipProvider">
connectionStringName=""
enablePasswordRetrieval="false"
enablePasswordReset="true"
requiresQuestionAndAnswer="false"
applicationName="ChangeControl"
requiresUniqueEmail="true"
passwordFormat="Encrypted"
maxInvalidPasswordAttempts="1000"
minRequiredPasswordLength="6"
minRequiredNonalphanumericCharacters="0"
passwordAttemptWindow="10"
passwordStrengthRegularExpression="^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{6,15}$"
type="Blah.Blah"/>
</add></providers>
</membership>