ttyUSB0 removed by brltty

I have an usb-to-uart device with FTDI chip.  After plug in, the dmesg show below message:

[ 5564.288020] usb 3-2: new full speed USB device using uhci_hcd and address 4
[ 5564.484151] usb 3-2: New USB device found, idVendor=0403, idProduct=6001
[ 5564.484155] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 5564.484159] usb 3-2: Product: FT232R USB UART
[ 5564.484161] usb 3-2: Manufacturer: FTDI
[ 5564.484164] usb 3-2: SerialNumber: A4008X3f
[ 5564.484282] usb 3-2: configuration #1 chosen from 1 choice
[ 5564.492214] ftdi_sio 3-2:1.0: FTDI USB Serial Device converter detected
[ 5564.492247] usb 3-2: Detected FT232RL
[ 5564.492249] usb 3-2: Number of endpoints 2
[ 5564.492252] usb 3-2: Endpoint 1 MaxPacketSize 64
[ 5564.492254] usb 3-2: Endpoint 2 MaxPacketSize 64
[ 5564.492257] usb 3-2: Setting MaxPacketSize 64
[ 5564.493216] usb 3-2: FTDI USB Serial Device converter now attached to ttyUSB0
[ 5569.353619] usb 3-2: usbfs: interface 0 claimed by ftdi_sio while 'brltty' sets config #1
[ 5569.356384] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[ 5569.356471] ftdi_sio 3-2:1.0: device disconnected

It was attached to ttyUSB0, but been removed after 5 seconds. seems like removed by brltty.
Here
http://www.plugcomputer.org/plugwiki/index.php/Serial_terminal_program
notes , in this case, remov the brltty.
So,

$ sudo aptitude purge brltty

The issue was gone! :)