I routinely receive notifications of obviously spammy Twitter users following me, e.g. accounts with names like @freemoneynow, etc. Is there a danger in allowing them to follow me if I do not follow them back? They could always send me a direct message with a phishing link, but aside from that, is this something I should be aware of? It becomes a maintenance headache if I have to actively prune my list of followers (admittedly not huge, but all it takes is one bad apple).