Is there a legitimate reason for a user to receive status messages about himself when connected to ejabberd?

I'm seeing a lot of messages go by that look something like this:

presence xmlns="jabber:client" from="user1@testing/10151390031321488767789003" to="User1@testing/10151390031321488767789003"

/presence

Are these valid presence messages for the XMPP protocol? What might be the origin, if they are valid?