An internet riddle is:
 
Q: How do trees get on the internet?
A: They log in.
 
“Q: How do trees get onto the internet? A: They log on” was posted to the newsgroup alt.cuddle on October 7, 2000.
 
   
Google Groups: alt.cuddle
Introduction to group
monkey puncher
10/7/00
(...)
I also really like bad jokes, so here is one :-
(and its awful)
(Sorry if you’ve all heard it before!)
 
Q:How do trees get onto the internet?
.
.
A: They log on…
 
Google Groups: alt.humor.puns
Puns of the Weak 01-17-03
Stan Kegel
1/17/03
(...)
How do trees get on the Internet?
They log in. (Sharnee,  12)
 
Google Books
Flight Path:
How WestJet is flying high in Canada’s most turbulent industry
By Paul Grescoe
Toronto, ON: John Wiley & Sons Canada Ltd.
2004
Pg. 233:
For something to do on those long winter nights!”) and sheer silliness (“How do trees get on the Internet? They log on”).
   
Google Books
December 2008, Boys’ Life, “Think & Grin,” pg. 59, col. 3:
Bill: How do trees get on the Internet?
Steve: Beats me.
Bill: They log in!
Luke Collins, Somers, NY.
 
Twitter
Jeff Korhan
‏@jeffkorhan
green humor from my son..“How do Trees get on the Internet?”  - They Log In.
8:07 PM - 4 Dec 2008
 
Twitter
Vicki Alderton
‏@MosherAngel
How do trees get on the internet?.....They LOG IN!
9:48 AM - 13 Mar 2009
 
Google Groups: Slifka 2013
Shabbat shalom… A riddle: How do trees access the internet?
Byron Edwards
1/30/15
They log on!   
 
Google Books
Rad Jokes
By Jack Jokes
PeteyRF Creative
2016
Pg. ?:
How do trees access the internet?
They log in.
 
Google Books
1001 Kid’s Jokes
By Kay Barnham
London: Arcturus Publishing
2016
Pg. ?:
How do trees get on the internet?
They log in.