Most of this could be pre-assembled in a back pack or duffel bag, so that you just need to pull out the extension cord and find a power jack plug it in, and then switch the telephone wire from a plugged in telephone, reach into your bag and hit the enter key, wait for 10 seconds , take a peek inside the bag, and then disconnect. You could write a script to post a whole series of messages and responses to previously viewed content. The whole thing could take between 10 seconds to 5 minutes to post everything disconnect, zip your bag up, reconnect the phone, and walk out.

Better if its an old laptop with a built in soft modem (less stuff to plug in, just the phone cable), you could just walk in with the laptop under your armpit open it up and stand next to the phone, and if someone happens to see you, you could act like you're trying to get wifi reception, while standing with your back to the phone jack concealing the wire.

Dumdy dum dumdy dum, unplugs phonejack, no wifi here...guess I'll mossy on by. Walk out of the building and don't return or reuse for a year or more, or ever, and cycle to the next location.

A resourceful person should be able to find 50-100 different accessible telephone jacks in their city. You'll use this method for postings that you will or may get in trouble for. Run of the mill postings can be done from a smaller set of locations which don't overlap with your sensitive locations. 100 phone jacks for quick anonymous trouble posting, 20 re-usable phone jacks for casual browsing, and casual "Anonymous" posting. And maybe 2 or 3 longer duration locations where you can to connect from and browse for 30mins to an hour at your leisure for reading and saving messages to floppy disk. And never from work or home connections.

If you get caught browsing the BBS from the leisure locations (which shouldn't happen if you're careful), there is no way to prove that you are the trouble poster, unless you're retarded and confess to it. Use different laptops for each class of activity (3 laptops, each encrypted with different keys).