Since the summary section is open to anyone to edit (like a wiki entry), any user should have the ability to view the edit history of an entry and have the option to revert to a previous edit if necessary.
The creator of the link entry should have some authority though. So I suggest having the option for the person submitting the entry to block out edits from other users.
Since the summary section is open to anyone to edit (like a wiki entry), any user should have the ability to view the edit history of an entry and have the option to revert to a previous edit if necessary.