Dota 2 now requires a linked phone number to play ranked matches, similar to what CS:Go does.

The goal is, among other things, to prevent smurfing. Smurfing, for those who don't know, is to create a low rank dota account for a number of reasons, among them...

- Quicker queue times for super high level players due to a bigger pool of players at low levels

- Practice new buids, play with friends or just enjoy a easier match..

- Ranking up the low level account and eventually selling it.

- Griefing other players since you have nothing to lose.

Obviously, the requirement of a phone number isn't the biggest hurdle to jump. People may "borrow" one from their relatives / friends or just buy a spare one, but I feel Valve isn't concerned about people who have a single alt account, what they are trying to prevent is griefers and account sellers to having a easy time.

And yes, griefers and sellers may still do the whole phone link thing but this involve now more time and money as opposed to clicking 3 buttons and setting a new account.

All in all, I think it's a nice step into a better future. People will stll insta-pick Pudge,ping mid and call you cyka, but it's Dota we are talking about here.