In what way is uploading the music you bought to private cloud storage illegal?
Google Music asked me to upload songs and I did. Is Google really going to get sued to oblivion? I doubt it.
Google Music asked me to upload songs and I did. Is Google really going to get sued to oblivion? I doubt it.
In the UK its technically illegal to rip a CD to your own PC to back it up, for example, see the recent high court case(s) about it where the government won against Brennan (who make hifi gear which can do this) - no different to this app.
Part of the reason google/youtube are quasi-monopolistic is that they've already been through all of this, they've had the arguments and the lawsuits in various different territories, and they've reached agreements and paid money to deal with the copyright issues.
The same can't be said for OP who probably doesn't have the time or money to fight it as evidenced by this post.