I recently received and email sent by a concerned person to all their friends warning of a new poisonous spider in the US, hiding in airline toilets of all places. This, like most apocryphal emails is a hoax. http://www.snopes.com/horrors/insects/telamonia.asp
It is hard not to just believe that these are real and warn everyone about the dangers, just in case. We would all feel bad if someone was bitten in the airplane facilities. The truth is that sending these things around is worse. The misinformation and lies just get everyone worried and then the one email to our close friends becomes a billion messages to the world just to keep them safe.
Please when you get these either have a good laugh and ignore them, or go to http://www.snopes.com to check, and then laugh and ignore them. Your friends will thank you for not filling up their email with stuff, and you will sleep easier at night knowing that the spiders are not in the toilets of planes waiting to bite.