Lol... yea that sucks. I happen to be on Optimum Online so it works hassle free.
I totally understand how you guys feel and I wish there was more tennis fans who demand genuinely free streams. Until then you have alternatives. I shared a link to a quality stream in this thread, it's from Australia and covers the AU open.
tvstream.hopto.org OR tvstream.hopto.org:8080 in VLC
You guys also have Supersport (sslsd)and Eurosport(sopcast) covering the AU open. Check wiziwig.tv -> live sport -> tennis for links.
There are free quality alternatives that are as good, more flexible and less demanding than espn3's service. You can't even choose the quality of the stream, it constantly tries to bump everything up to HD thus degrading the quality of any simultaneous streams. My favorite Grand Slam to stream is USopen because of it's simple functional design. Built by IBM with full features like rewind, a MUCH faster match swap and picture-in-picture.
ESPN is a greedy cooperate entity that would monopolize access to all live sports if they could and Tennis Channel is just pathetic