http://us.battle.net/wow/en/forum/to...0477954?page=1
<removing link as it explains actually too much>
These two links should explain what people are doing.
The gist of it is, don't import auras unless you trust the source. If you DO import an aura from an untrusted source, transfer the bulk of your gold off-character before the import, leave a few silver. Walk up to a mailbox and open the 'Send Mail' tab. If your silver pieces are still there, the aura is safe.
I'd post this tip on the wow forums, but I'm not currently subbed.
Edit: The author of Weakauras 2 has patched the addon to prevent this behavior. Please update to the latest version (2.0.1) to protect yourself.