Directly answering your question, Stalker is not asking for a donation. As someone already stated. Stalker is just software and no it is not illegal. Now NFPS and others do provide services that allow you to use the Stalker software to get IPTV and they want to get paid for providing you with content. Now if this content is obtained legally or not... well who knows but probably not. Are you going to get in trouble for it, well who knows, it may depend where you live. Streaming in general should not be illegal but there is a gray area. Downloading copyright stuff is illegal but streaming does not download anything typically. The gray area is that any portion downloaded could be considered piracy and that could happen if your buffering to disk. Unlike IKS where you knowingly modify hardware to make the receiver work to gain access to pirated satellite, streaming you are not modifying anything. There are plenty of places to get legal and illegal streams. How do you know if they are or are not. Do you read the providers contracts to see if everything is legit? How do you know if Hulu is legit? Have you read their contracts or Netflix or any other streaming provider? If you don't want to expose yourself to the risk then don't. Only you can decide what risk level is acceptable to you. Just go do some research about streaming.
