There is strong evidence that bitcoinplus.com is a scam.
The website claims that a miner must have earned at least 0.01 BTC before he can transfer the money to his account. After spending two weeks mining on several machines, I finally earned 0.01 BTC. Just as I was about to make the transfer, the website notified me that a 0.01 BTC transaction fee was to be charged. I did not have sufficient money, so I kept on mining, hoping to earn 0.02 BTC by next week.
Today, however, I noticed several strange events. First, the payout used to be 851 satoshis per share submitted; now it had mysteriously become 721 satoshis per share submitted. Second, although my miners were submitting work, the payout slowly ceased---until I was not getting any payout at all, while all my CPU cores were busy mining at 100%. An hour ago, the site's web server went down.
I am not going to mine at bitcoinplus.com any more.