2. Change MAC address?
3. Create new account on Blogger/Tumblr/etc.
Yes fuck Chinese government, but 5 years later western governments will follow this way
I don't want to minimize the assault on our privacy and anonymity from all directions, but the one positive trend in the US and Canada has been toward less ID or no ID for using Internet cafes.
I remember the early days of Internet cafes in North America, and they very often wanted to see ID.
These days there are lots of public wifi hotspots, where at most they ask for an email address (a throwaway email address works fine). The purpose of collecting an email address appears to be CYA -- they get some assurance that you've agreed to their Terms and Conditions.
Some of the "western" bars even have a vpn running so you can browse facebook when connecting to their wifi.
The danger of retaining your real MAC should be obvious; it's a unique identifier specific to your machine that will at least significantly narrow the scope of the machine/owner your adversaries are looking for if it doesn't give the investigators a direct link back to you (e.g., manufacturer records MAC addresses next to serial numbers, adversary gains access to manufacturer's data and sees "MAC X / Serial No Y sold to consumer Z online").
Depending on the configuration of the router on the open access points, it may be possible to retrieve a list of all connected MACs over the whole lifetime of the router. Then they simply have to correlate, "OK, which machines had a lease when the access from this machine was made?", and then investigate the 5 matches that come up.
This is not very safe, clearly.
That aside, MAC addresses can be easily changed and spoofed.
If one was really concerned, a throw away USB WiFi dongle could be used.