Does it matter, whether the people are volunteers, paid or coerced? The fact stands that Israel is making a concerted effort to influence social media in their favor.

I find it a bit silly, that you want proper sources and then just say you don't trust a major Israeli newspaper without further explanation. Especially since the BBC deemed it credible as a source.

For the last link how is it "only slightly related?" It is a private company that is operating from Israel, run by ex-intelligence people, influencing elections world wide. This kind of things are not sold with a google add, but instead require extensive networks and contacts. It is implausible, that the company operated without the knowledge and approval of the Israeli government. Also the article states that the company was promoted on the website of the Israeli ministry of defense. Finally Israeli intelligence has proven competent in many activities around the globe, but in particular in regards to digital activities (stuxnet). There is no reason to belief that they wouldn't have picked up on one of their former employees running these kind of activities.