Yes.
But the good news is, you can fix that. Use 128-bit WEP encryption. The generally recommended setup for a home network is to use "Open Authentication" with "Shared Key", which means you will need to enter the same key value into every device connecting to your network. (If you have a wireless printer, you may need to hook it up wired temporariliy to set this key.)
For an additional layer of protection, you should be able restrict the ehternet card MAC addresses allowed on the network. Fire up all the machines at once, and add them to the "allowed" list.
I recently installed a wireless router and am only using mac address filtering for security. Is it enough? Seems like it would be since it will only allow mac addresses from my exception list to access the network.
Should I enable encryption as well?
Anyone?