diff --git a/cmd/wf/commands.go b/cmd/wf/commands.go
index c252e6a..a725429 100644
--- a/cmd/wf/commands.go
+++ b/cmd/wf/commands.go
@@ -15,9 +15,25 @@ import (
 
 func requireAuth(f cli.ActionFunc, action string) cli.ActionFunc {
 	return func(c *cli.Context) error {
+		// check for logged in users when host is provided without user
+		if c.GlobalIsSet("host") && !c.GlobalIsSet("user") {
+			// multiple users should display a list
+			if num, users, err := usersLoggedIn(c); num > 1 && err == nil {
+				return cli.NewExitError(fmt.Sprintf("Multiple logged in users, please use '-u' or '-user' to specify one of:\n%s", users), 1)
+			} else if num == 1 && err == nil {
+				// single user found for host should be set as user flag so LoadUser can
+				// succeed, and notify the client
+				if err := c.GlobalSet("user", users[0]); err != nil {
+					return cli.NewExitError(fmt.Sprintf("Failed to set user flag for only logged in user at host %s: %v", users[0], err), 1)
+				}
+				fmt.Printf("Host specified without user flag, using logged in user: %s\n", users[0])
+			} else if err != nil {
+				return cli.NewExitError(fmt.Sprintf("Failed to check for logged in users: %v", err), 1)
+			}
+		}
 		u, err := config.LoadUser(c)
 		if err != nil {
-			return cli.NewExitError(fmt.Sprintf("couldn't load config: %v", err), 1)
+			return cli.NewExitError(fmt.Sprintf("Couldn't load user: %v", err), 1)
 		}
 		if u == nil {
 			return cli.NewExitError("You must be authenticated to "+action+".\nLog in first with: "+executable.Name()+" auth <username>", 1)
diff --git a/cmd/wf/main.go b/cmd/wf/main.go
index 46de71d..7cce4c9 100644
--- a/cmd/wf/main.go
+++ b/cmd/wf/main.go
@@ -148,7 +148,7 @@ func main() {
 			Name:        "posts",
 			Usage:       "List all of your posts",
 			Description: "This will list only local posts.",
-			Action:      commands.CmdListPosts,
+			Action:      requireAuth(commands.CmdListPosts, "posts"),
 			Flags: []cli.Flag{
 				cli.BoolFlag{
 					Name:  "id",
@@ -170,7 +170,7 @@ func main() {
 		}, {
 			Name:   "blogs",
 			Usage:  "List blogs",
-			Action: commands.CmdCollections,
+			Action: requireAuth(commands.CmdCollections, "blogs"),
 			Flags: []cli.Flag{
 				cli.BoolFlag{
 					Name:  "tor, t",
@@ -189,7 +189,7 @@ func main() {
 		}, {
 			Name:        "claim",
 			Usage:       "Claim local unsynced posts",
-			Action:      commands.CmdClaim,
+			Action:      requireAuth(commands.CmdClaim, "claim"),
 			Description: "This will claim any unsynced posts local to this machine. To see which posts these are run: wf posts.",
 			Flags: []cli.Flag{
 				cli.BoolFlag{
@@ -229,7 +229,7 @@ func main() {
 		{
 			Name:   "logout",
 			Usage:  "Log out of a WriteFreely instance",
-			Action: cmdLogOut,
+			Action: requireAuth(cmdLogOut, "logout"),
 			Flags: []cli.Flag{
 				cli.BoolFlag{
 					Name:  "tor, t",
diff --git a/commands/commands.go b/commands/commands.go
index 41b0662..19119b1 100644
--- a/commands/commands.go
+++ b/commands/commands.go
@@ -357,18 +357,18 @@ func CmdClaim(c *cli.Context) error {
 }
 
 func CmdAuth(c *cli.Context) error {
+	username := c.Args().Get(0)
 	// Check configuration
 	u, err := config.LoadUser(c)
 	if err != nil {
 		return cli.NewExitError(fmt.Sprintf("couldn't load config: %v", err), 1)
 	}
-	if u != nil && u.AccessToken != "" {
-		return cli.NewExitError("You're already authenticated as "+u.User.Username+". Log out with: "+executable.Name()+" logout", 1)
+	if u != nil && u.AccessToken != "" && username == u.User.Username {
+		return cli.NewExitError("You're already authenticated as "+u.User.Username, 1)
 	}
 
 	// Validate arguments and get password
 	// TODO: after global config, check for default user
-	username := c.Args().Get(0)
 	if username == "" {
 		return cli.NewExitError("usage: "+executable.Name()+" auth <username>", 1)
 	}