The reason why people often claim that "service" shorts pennies like VOIS, is due to the fact that they usually only do a video chart for penny stocks AFTER they have already ran big on heavy volume... They do not chart stocks while they are forming a bottom/basing, they wait until excitement is near the peak, so they can attract more people to the paid service, by advertising in the video.
... and doing a video about any penny stock, after the volume/price are near a peak, is going to result in lots of big drops shortly after making the video, because very few penny stocks hold their gains.
The big losses shortly after that "service" shows up, is the reason why people think its shorting... when in reality they are just looking for high interest stocks to advertise on, not entry levels where people can actually make money.
Personally, id rather be early to a big run than catching the tail end like the people following those video advertisements.