Temporary IP blocks just work to block that person for that session (in sense of time) in cases where login is not required or can easily be created (like wikipedia). In most cases the people are incapable (through willingness or technical restriction) of changing their IP address and they move on. Short term IP blocks work wonderfully for this.
At least for services like wikipedia which do not require registration for making changes, (which is a great usp), temp IP bans are the best and possibly only solution except for browser fingerprinting.
Other services that require an account creation, like twitter can easily block users and require something like a phone number for known problematic IPs. As can be seen here.
- There might be a bigger uproar if they started doing this than twitter asking for a phone number if you are on a blacklisted IP.
I block connections from most of the world to my various network resource admin points because only I am going to be connecting to them and I'm not going to be connecting from China or Nigeria or Romania. And if I am, I unblock them temporarily.